Method and system for estimating gas supply pressure

Abstract

Methods and systems for estimating gas supply pressure are described herein. The method may include measuring a run-time valve duty cycle of a valve of the gas chromatography system. The method may include estimating a run-time supply pressure from at least one of a run-time flow rate or a downstream pressure and a run-time valve duty cycle based on one or more calibrated valve duty cycles corresponding to one or more calibrated supply pressures and one or more calibrated flow rates. The method may include, in response to determining that the runtime supply pressure is greater than the threshold supply pressure value, generating a notification that the runtime supply pressure is greater than the threshold supply pressure value.

Description

Cross Reference to Related Applications

[0001] This application claims the benefit and priority of U.S. Patent Application No. 18 / 448,827, filed August 11, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application generally relates to gas chromatography. Background Technology

[0003] Gas chromatography (GC) is used to analyze and detect the presence of many different substances in a sample. The function of a gas chromatograph is to separate the components of a chemical sample (called analytes) and detect the identification and / or concentration of those components. This separation is typically accomplished using a capillary GC column. In some cases, this column is essentially a molten silica tube with a stationary phase coating on the inside, which interacts with the sample to separate the components. A pressurized gas, called the mobile phase, is used to propel the sample through the column. GC columns can be kept isothermal throughout the analysis or subjected to a gradual temperature change. Summary of the Invention

[0004] Measuring the pressure of a storage tank or other pressurized gas source coupled to a GC system or gas chromatograph can be expensive and complex. The solution described in this article provides a method for estimating gas supply pressure without adding additional hardware to the GC system.

[0005] At least one aspect of this disclosure relates to a method for estimating the gas supply pressure of a gas chromatography system. The method may include measuring the operating valve duty cycle of a valve in the GC system. The method may include estimating the operating supply pressure from at least one of the operating flow rate or downstream pressure and the operating valve duty cycle, based on one or more calibration valve duty cycles corresponding to one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. The method may include generating a notification that the operating supply pressure is greater than a threshold supply pressure value in response to determining that the operating supply pressure is greater than a threshold supply pressure value.

[0006] Another aspect of this disclosure relates to a gas chromatography system. The system may include valves. The system may include an electro-pneumatic control module. The electro-pneumatic control module can measure the operating valve duty cycle. The electro-pneumatic control module can estimate the operating supply pressure from at least one of the operating flow rate or downstream pressure and the operating valve duty cycle, based on one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. The electro-pneumatic control module can generate a notification that the operating supply pressure is greater than a threshold supply pressure value in response to determining that the operating supply pressure is greater than a threshold supply pressure value.

[0007] Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features, and advantages of the devices and / or processes described herein will become apparent from the detailed description set forth herein and, in connection with the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0008] The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

[0009] Figure 1 is a schematic diagram of a GC system according to an embodiment.

[0010] Figure 2 is a schematic diagram of an electronic pneumatic control module and detector of a GC system according to an embodiment.

[0011] Figure 3 is a schematic flowchart of a method for estimating a gas supply pressure according to an embodiment.

[0012] Figure 4 is a plot of valve duty cycle versus supply pressure according to an embodiment.

[0013] The same reference numbers and designations in the various drawings indicate the same elements. DETAILED DESCRIPTION

[0014] The following is a more detailed description of various concepts related to methods, apparatus, and systems for estimating a supply pressure (e.g., a gas supply pressure) and implementations thereof. The various concepts introduced above and discussed in greater detail below can be implemented in any of numerous ways, as the described concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided for illustrative purposes only.

[0015] A GC system can be coupled with a tank or other pressurized gas source that supplies gas to the GC system. The supply gas can be pressurized gas that is supplied to injection ports and detectors of the GC system. For example, these gases can be carrier gases, such as helium, nitrogen, hydrogen, argon / methane mixtures, or other generally inert gases that provide flow through injection ports of the GC column and other flow path components of the GC system. These gases can also include fuel gas (e.g., air or hydrogen) as well as makeup and / or reference gases provided to detectors for proper operation of the detectors (e.g., inert gases similar to the carrier gases listed above). One or more gases can be supplied to each injection port or detector. It can be challenging to measure the precise pressure (e.g., supply pressure) of the pressurized gas source that supplies one or more gases to an injection port or detector of the GC system. For example, the system can have a sensor external to the GC system to provide the pressure of the pressurized gas source. The additional external sensor can increase the cost and complexity of the GC system. Moreover, the external sensor can not interface with the GC system in a manner that allows the GC system to take action if the supply pressure exceeds a defined threshold.

[0016] The present disclosure relates to methods and systems for estimating gas supply pressure. During a calibration process of an electronic pneumatic control module, valve duty cycles required to achieve a known flow rate or a known downstream pressure at a known supply pressure can be recorded. During operation of the GC system, the recorded valve duty cycles corresponding to various supply pressures at a given flow rate can be used in conjunction with a measured run-time valve duty cycle and at least one of a run-time flow rate or a run-time downstream pressure to estimate a run-time gas supply pressure.

[0017] The disclosed solutions have the technical advantage of detecting whether the supply pressure is above or beyond a specification. For example, if the supply pressure is higher than a pressure specification for proper operation of one or more valves on one or more gas supply flow paths to the GC system, the valves can lose their ability to control the flow of gas into the GC system. This can result in additional supply gas flowing through the GC system, causing gas waste. These solutions can provide an estimated supply pressure of the gas that can show whether the actual pressure of the pressurized gas source is within or outside of a specification for proper valve operation. These solutions can provide an estimated gas supply pressure without adding additional hardware to the GC system. These solutions can prevent over-pressurized gas from flowing through the valves.

[0018] Figure 1is a schematic diagram of a GC system 100. The GC system 100 can include a representative GC system. The GC system 100 can include one or more injection ports 105 (e.g., inlets, sample inlets). The injection ports 105 can receive a sample for analysis injected into the GC system 100. For example, a sample can be injected into the injection ports 105 at which the sample is vaporized into a gaseous state for analysis by the GC system 100 if not already in a gaseous state.

[0019] The GC system 100 can include one or more pressurized gas sources 110 (e.g., pressurized gas supply, gas source, gas supply, supply gas). The pressurized gas sources 110 can include a tank. The pressurized gas sources 110 (e.g., carrier gas supply, carrier gas source, carrier gas) can be fluidically (e.g., in fluid) coupled (e.g., connected) with the injection ports 105. The pressurized gas sources 110 can supply a carrier gas, such as, but not limited to, helium, hydrogen, nitrogen, argon / methane mixture, or other such inert gas, that transports the injected sample from the injection ports 105 through the GC system 100. The pressurized gas sources 110 can include a source of pressurized gas. The pressurized gas sources 110 can be a gas distribution system of pressurized gas. The pressurized gas can be found in a laboratory. The pressurized gas sources 110 can include a plurality of gases. The pressurized gas sources 110 can be coupled with the GC system 100 via a distribution panel.

[0020] The GC system 100 can include one or more electronic pneumatic control (EPC) modules 140 (e.g., flow control modules). The electronic pneumatic control modules 140 can be coupled (e.g., connected) with the pressurized gas source 110. The electronic pneumatic control modules 140 can be fluidly coupled with the injection port 105. For example, the injection port 105 can be attached to the electronic pneumatic control module 140. The electronic pneumatic control module 140 can control the flow and / or pressure of the injection port 105. The carrier gas can travel to the first electronic pneumatic control module 140 before traveling to the injection port 105. The electronic pneumatic control module 140 can use one or more calibration values or curves to estimate the gas supply pressure. The calibration values or curves can be generated during the production of the electronic pneumatic control module 140 and / or the GC system 100. For example, one or more calibration values or one or more calibration curves can be generated by setting a flow rate, setting the supply pressure to a value, and then recording the duty cycle at that supply pressure value. This process can be repeated for additional supply pressures to get additional duty cycles as needed to calibrate the valve. This process can be repeated for different flow rates until the entire range of allowed flow rates is exhausted. The one or more calibration values or one or more calibration curves can be stored. The calibration curves can be generated for each different gas type. The one or more calibration values or one or more calibration curves can be generated for each valve in the GC system 100. A calibration module including a plurality of calibration values or curves can be stored on the electronic pneumatic control module 140. Each inlet can have its own electronic pneumatic control module 140. Each electronic pneumatic control module 140 can be coupled with the same gas supply or a different gas supply. The electronic pneumatic control module 140 can measure the runtime valve duty cycle.

[0021] The GC system 100 can include one or more columns 115. The columns 115 can be fluidly coupled with the injection port 105. The columns 115 can be selected from a wide variety of columns used to effect separation of components of a sample by gas chromatography. GC systems configured for backflush, detector split, or other pneumatic switching can include multiple columns. The carrier gas can transport the sample to the columns 115 for separation. The columns 115 can separate components of a gaseous sample to produce one or more analytes of interest for analysis by the GC system 100. The columns 115 can include capillary columns and / or can include a fused silica tubing having a coating (e.g., a stationary phase coating) on an interior portion of the tubing that interacts with a sample injected into the injection port 105 to separate components of the sample. The dimensions of the columns 115 can include an inner diameter ranging from 50 micrometers to 530 micrometers and a length ranging from 1 meter to 200 meters. The injection port 105 can provide the sample to the columns 115.

[0022] The GC system 100 can include one or more detectors 120. The detectors 120 can receive separated components (e.g., analytes of a sample) after the sample is transported through the column 115. The detectors 120 can be fluidly coupled with the column 115. The detectors 120 can analyze the separated sample components to detect the presence and / or quantity of sample analytes separated by the column 115. The detectors 120 can include a flame ionization detector (FID), a mass selective detector (MSD), a thermal conductivity detector (TCD), an electron capture detector (ECD), a nitrogen phosphorus detector (NPD), a sulfur chemiluminescence detector (SCD), a nitrogen chemiluminescence detector (NCD), a flame photometric detector (FPD), or a helium ionization detector (HID), among others.

[0023] The detectors 120 can be fluidly coupled with the electronic pneumatic control module 140. For example, the detectors 120 can be attached to the electronic pneumatic control module 140. The electronic pneumatic control module 140 can control the flow and / or pressure of gas to the detectors 120. The gas can originate from the pressurized gas source 110. The pressurized gas source 110 can be fluidly coupled with the detectors 120. The pressurized gas source 110 supplied to the detectors 120 can include makeup gas, reference gas, air, or any other inert gas. The pressurized gas source 110 supplied to the detectors 120 can increase the flow to the detectors 120. The pressurized gas source 110 supplied to the detectors 120 can provide fuel to ignite a flame (such as in an FID). Each detector 120 can have its own electronic pneumatic control module 140.

[0024] The GC system 100 can include one or more column heaters 125. The column heaters 125 can include an oven, a convection heater, a conductive heater, an air bath, or other such heating devices for heating certain GC system components. The column heaters 125 can heat or cool the column 115 and other flow path components to a desired temperature. The column heaters 125 can be configured to heat the column 115 such that the column 115 remains isothermal during sample analysis.

[0025] The GC system 100 can include one or more controllers 130. The controller 130 can be communicably connected, directly or indirectly, to the detector 120, the column heater 125, the injection port 105, one or more sensors, and / or other components of the GC system 100. The controller 130 can be an onboard computing component physically incorporated into a housing (e.g., a GC system housing) of the GC system 100 that houses the column 115, the detector 120, the column heater 125, and other components of the GC system 100. The controller 130 can be one or more separate computing devices and / or other such control devices that are internal and / or external to the GC system housing. The controller 130 or a portion of the controller 130 can reside within the electronic pneumatic control module 140. For example, the controller 130 or a portion of the controller 130 can be disposed in the electronic pneumatic control module 140. The controller 130 or a portion of the controller 130 can reside within the GC system 100. For example, the controller 130 or a portion of the controller 130 can be disposed in the GC system 100. The controller 130 can be split between multiple locations. The controller 130 can be disposed external to the electronic pneumatic control module. The controller 130 can be disposed external to the GC system 100. The controller 130 can calculate or estimate a runtime supply pressure. The controller 130 can estimate the runtime supply pressure from at least one of a runtime flow rate or a downstream pressure and a runtime duty cycle. The controller 130 can compare the estimated runtime supply pressure to a threshold supply pressure value. The controller 130 can generate a notification that the runtime supply pressure is greater than the threshold supply pressure value in response to determining that the runtime supply pressure is greater than the threshold supply pressure value.

[0026] The controller 130 can include one or more processors, such as but not limited to a single-core processor, a multi-core processor, a logic device, or other such data processing circuitry, configured to execute, analyze, and process data and information of the GC system 100. The controller 130 can include a non-transitory memory device communicably connected to the processor. The memory device can be configured as a volatile memory device (e.g., SRAM and DRAM), a non-volatile memory device (e.g., flash memory, ROM, and hard drives), or any combination thereof. The memory device can store executable code and other such information generated and / or processed by the processor during operation of the GC system 100.

[0027] The GC system 100 can include one or more input / output devices communicably connected to the controller 130. The input / output devices can enable an operator and / or user to receive information from the controller 130 and input information and parameters into the controller 130. Such information and parameters can be stored in a memory device, accessed by the processor, and output to the input / output devices. For example, the input / output devices can include a monitor, display device, touchscreen device, keyboard, microphone, joystick, dial, button, or other such devices to enable the input and output of information and parameters. The input / output devices can be used to input information into the controller 130 and output or otherwise display information and data generated by the processor of the GC system 100.

[0028] Figure 2is a schematic diagram of the electronic pneumatic control module 140 and the detector 120 of the GC system 100. The electronic pneumatic control module 140 can control the flow of gas to one or more detectors and / or one or more injection ports of the GC system 100, and can include a separate flow path 215 for each type of gas fluidly connected to the electronic pneumatic control module 140. The flow path 215 can include a valve 205. The valve 205 can be fluidly coupled with the pressurized gas source 110. The valve 205 can be fluidly coupled with the detector 120. For example, the valve 205 can control the passage of gas from the pressurized gas source 110 through the flow path 215 to the detector 120. The valve 205 can receive gas from the pressurized gas source 110. For example, the valve 205 can receive H2 gas, make-up gas, or air, among others, from the pressurized gas source 110. The make-up gas can include nitrogen or helium. One or more pressure sensors 220 can be disposed downstream of the valve 205. The pressure sensor 220 can measure the downstream pressure of the gas flowing from the valve 205 to the detector 120. The valve 205 can dynamically control the flow of gas to the detector 120 using the downstream pressure measured by the pressure sensor 220 downstream of the valve 205, the pressure of the detector 120, and the known restriction (e.g., flow restrictor 225) between the pressure sensor 220 downstream of the valve 205 and the detector 120. The duty cycle of the valve 205 can control the flow of gas to the detector 120. The duty cycle can be defined as the percentage of time that the valve is open or receiving a certain control signal. The valve 205 can not function properly if the supply pressure of the gas upstream of the valve 205 is above a certain pressure. For example, the valve 205 can not close if the gas supplied to the valve 205 is above a specified threshold for the GC system 100. For example, the specified pressure can be 120 psi. The supply pressure threshold can be specified by the manufacturer of the valve 205. The GC system 100 can not have a pressure sensor disposed upstream of the valve 205. The valves 205 of the GC system 100 can be different types of valves. Each valve 205 can have a different supply pressure threshold, rather than a single threshold for the GC system 100.

[0029] The pressure sensor 220 downstream of the valve 205 can not be able to measure the pressure upstream of the valve 205 (e.g., upstream pressure or supply pressure). In some cases, the pressure sensor 220 downstream of the valve 205 is not able to measure the pressure upstream of the valve 205 because there is a restriction (e.g., tubing, channels in the EPC module, frit, etc.) in the flow path between the supply gas and the pressure sensor 220 downstream of the valve 205. The valve 205 can provide a restriction even when fully open. Thus, the pressure downstream of the valve 205 can not be exactly the same as the supply pressure. The pressure sensor 220 downstream of the valve 205 can only be able to measure the pressure downstream of the valve 205 (e.g., downstream pressure). The downstream pressure can not be representative of the supply pressure. The downstream pressure can be different than the supply pressure. The downstream pressure alone can not be sufficient to determine the supply pressure without knowing the valve duty cycle and / or the calibration curve.

[0030] The GC system 100 can include one or more electronic pneumatic control modules 140. The electronic pneumatic control modules 140 can include a controller 130. The controller 130 can be separate from the electronic pneumatic control modules 140. The electronic pneumatic control modules 140 can include a portion of the controller 130. The electronic pneumatic control modules 140 can measure a runtime valve duty cycle of the valve 205. The electronic pneumatic control modules 140 can estimate a runtime supply pressure from at least one of a runtime flow rate or downstream pressure and the runtime valve duty cycle based on one or more calibration valve duty cycles corresponding to one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. For example, the electronic pneumatic control modules 140 can estimate a runtime supply pressure from at least one of a runtime flow rate or downstream pressure and the runtime valve duty cycle based on one or more calibration valve duty cycles corresponding to one or more calibration supply pressures at one or more calibration flow rates or calibration downstream pressures. The diagnostic program can use a single calibration flow rate. For example, the diagnostic program entering a mode of the same set flow rate as the calibration flow rate can use a single calibration flow rate. This can eliminate the need to calibrate for more than one flow rate, potentially reducing calibration complexity and time. The diagnostic program can use a single calibration downstream pressure. For example, the diagnostic program entering a mode of the same set flow rate as the calibration downstream pressure can use a single calibration downstream pressure. The downstream pressure can be the pressure of the gas downstream of the valve 205. The downstream pressure can depend on the flow rate, gas type, restriction, pressure, and / or temperature.

[0031] The electronic pneumatic control module 140 can determine that the runtime supply pressure is greater than, less than, or equal to a threshold supply pressure value. For example, the threshold supply pressure value can be in a range of 130 psi to 200 psi. The threshold supply pressure value can be specified based on a valve manufacturer's recommendation. The threshold supply pressure value can include a factor of safety (e.g., a safety factor) beyond the manufacturer's recommendation. The safety factor can reduce or eliminate false positives. The electronic pneumatic control module 140 or the GC system 100 can generate a notification in response to the runtime supply pressure being greater than, less than, or equal to the threshold supply pressure value.

[0032] The electronic pneumatic control module 140 can include an EEPROM. For example, the EEPROM can store each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures for each flow rate. The EEPROM can store each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and a respective calibration flow rate or a downstream pressure of the one or more calibration flow rates. The EEPROM can store each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and a downstream pressure. The electronic pneumatic control module 140 can estimate the runtime supply pressure from the calibration values, tables, and / or curves. The valve 205 can be disposed in the electronic pneumatic control module 140. For example, the valve 205 can be disposed in the electronic pneumatic control module 140 of the GC system 100. Each of the one or more electronic pneumatic control modules 140 can have more than one gas, flow path, or valve 205. The electronic pneumatic control module 140 can control the flow to the detector 120 or the injection port 105.

[0033] The GC system 100 can include a pressurized gas source 110. The pressurized gas source 110 can be external to the electronic pneumatic control module 140. The pressurized gas source 110 can be fluidically coupled with the valve 205. The pressurized gas source 110 can hold a gas. For example, the pressurized gas source 110 can hold a H2 gas, a makeup gas, or air, among others. The pressurized gas source 110 can provide the gas to the GC system 100. For example, the pressurized gas source 110 can provide the gas to the detector 120. The pressurized gas source 110 can provide a pressurized gas to the GC system 100. For example, the pressurized gas source 110 can provide a pressurized H2 gas, a pressurized makeup gas, or a pressurized air to the GC system 100. The pressurized gas source 110 can be a gas distribution system. For example, the pressurized gas source 110 can be a gas distribution system of pressurized gas.

[0034] The GC system 100 can include a detector 120. The detector 120 can be fluidly coupled with the column 115. The detector 120 can receive sample analytes and carrier gas from the column 115. The detector 120 can also be fluidly coupled with a valve 205. For example, the detector 120 can be fluidly coupled with the valve via a flow path 215 through the electronic pneumatic control module 140. The valve 205 can be disposed upstream of the detector 120. For example, the valve 205 can be disposed upstream of the detector 120 of the GC system 100. The detector 120 can be disposed downstream of the valve 205. The valve 205 can be disposed in the electronic pneumatic control module 140. For example, the valve 205 can be disposed in the electronic pneumatic control module 140 of the GC system 100. The valve 205 can be disposed in the flow path 215 connecting the supply gas to the detector 120.

[0035] In some embodiments, the GC system 100 includes an injection port 105 (e.g., an inlet). The injection port 105 can be coupled with the electronic pneumatic control module 140. For example, the injection port 105 can be attached to the electronic pneumatic control module 140. Each detector 120 can have a corresponding electronic pneumatic control module 140. Each injection port 105 can have a corresponding electronic pneumatic control module 140. The electronic pneumatic control module 140 corresponding to the detector 120 can be different or the same as the electronic pneumatic control module 140 corresponding to the injection port 105. The electronic pneumatic control module 140 can use one or more calibration curves, tables, or values to estimate the gas supply pressure. The systems and methods of the present disclosure can be used for the electronic pneumatic control module 140 to provide a gas flow to the injection port 105. The injection port 105 can be fluidly coupled with the valve 205. The injection port 105 can provide a sample to the column 115.

[0036] Figure 3 is a schematic flow chart illustrating a method 300 for estimating a gas supply pressure. For example, the method 300 can include estimating a gas supply pressure of a GC system 100. The method 300 for estimating a supply pressure can include a diagnostic procedure. Briefly, the method 300 can include measuring a calibration valve duty cycle (block 305). The method 300 can include measuring a runtime valve duty cycle (block 310). The method 300 can include estimating a runtime supply pressure (block 315). The method 300 can include determining that the runtime supply pressure is greater than a threshold supply pressure value (block 320). The method 300 can include generating a notification (block 325).

[0037] Method 300 can include measuring calibration valve duty cycles (block 305). For example, method 300 can include measuring one or more calibration valve duty cycles. The calibration valve duty cycles can include duty cycle values for valve 205. For example, the calibration valve duty cycles can include duty cycle values measured during a calibration process for valve 205. The one or more calibration valve duty cycles can be measured to calibrate valve 205. For example, the one or more calibration valve duty cycles can be measured prior to GC system 100 being at a customer site (e.g., a laboratory) (e.g., when GC system 100 is being built at a production facility). Method 300 can include measuring one or more calibration valve duty cycles, each of the one or more calibration valve duty cycles corresponding to one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. The calibration supply pressures can include known pressures. For example, the calibration supply pressures can include known supply pressures used during a calibration process for valve 205. Method 300 can include measuring the one or more calibration valve duty cycles corresponding to the one or more calibration supply pressures and the one or more calibration flow rates or the downstream pressure.

[0038] If method 300 uses flow rate, valve 205 can need to be calibrated for multiple types of gases if the channel allows different types of gases. In some embodiments, a downstream pressure can be used instead of a flow rate. This can allow for a single calibration to be used for any type of gas. If method 300 is running a diagnostic program, a single flow rate or downstream pressure can be sufficient for calibration.

[0039] Method 300 can include calibrating valve 205. During calibration of valve 205 or prior to calibration of valve 205, a representative population of valves can be obtained and an equation with parameters can be obtained that describes the relationship between valve duty cycle and supply pressure at certain one or more flow rates or one or more downstream pressures. To calibrate each individual valve, the duty cycle at one or more different flow rates or one or more downstream pressures and one or more supply pressures can be measured to generate these parameters for that particular valve. Then, during runtime, this equation can be used to relate the runtime valve duty cycle to the runtime supply pressure at the runtime flow rate in order to estimate the runtime supply pressure. The relationship between valve duty cycle and supply pressure can be linear.

[0040] During calibration of an individual valve, a table of supply pressures and valve duty cycles can be generated for one or more flow rates or downstream pressures. Then, during runtime, the runtime flow rate or downstream pressure, the runtime valve duty cycle, and this calibration table can be used to estimate the runtime supply pressure using the table and / or interpolation.

[0041] The method 300 can include measuring each of the one or more calibration valve duty cycles required (e.g., needed) to achieve a target flow rate or a target downstream pressure at a respective calibration supply pressure. For example, the one or more calibration valve duty cycles to achieve a target flow rate at a known supply pressure can be measured. The target flow rate can include a flow rate of gas from the pressurized gas source 110 through the valve 205. The flow rate can be any flow rate used to measure the one or more calibration valve duty cycles corresponding to the one or more calibration supply pressures. The flow rate can be in a range of 0 mL / min to 100 mL / min. For example, the flow rate can be 30 mL / min.

[0042] The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective one of the one or more calibration supply pressures and a respective one of the calibration flow rates. For example, the method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective one of the one or more calibration supply pressures and a respective one of the calibration flow rates in the electronic pneumatic control module 140. The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective one of the one or more calibration supply pressures and a downstream pressure. The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective one of the one or more calibration supply pressures and a downstream pressure in the electronic pneumatic control module 140.

[0043] The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures for each given calibration flow rate. The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and corresponding to a respective calibration flow rate or a downstream pressure in the GC system 100 in an electronic pneumatic control module EEPROM. The method 300 can include storing each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and corresponding to a respective calibration flow rate in the electronic pneumatic control module 140 EEPROM. The one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and corresponding to a respective calibration flow rate can be stored in a map or table. The method 300 can include storing, by the controller 130 or the electronic pneumatic control module 140, each of the one or more calibration valve duty cycles corresponding to a respective calibration supply pressure of the one or more calibration supply pressures and corresponding to a respective calibration flow rate. There can be multiple valves 205 for each electronic pneumatic control module 140. There can be multiple electronic pneumatic control modules 140 for each GC system 100. Calibration data can be collected and stored for each valve 205.

[0044] The method 300 can include measuring a runtime valve duty cycle (block 310). For example, the method 300 can include measuring a runtime valve duty cycle of the valve 205. The method 300 can include measuring a runtime valve duty cycle of the valve 205 of the GC system 100. The runtime valve duty cycle can be measured at a customer site. The runtime valve duty cycle can be measured at any time after the valve 205 has been calibrated. The method 300 can include measuring, by the controller 130 or the electronic pneumatic control module 140, the runtime valve duty cycle.

[0045] Method 300 can include estimating a runtime supply pressure (block 315). For example, method 300 can include estimating the runtime supply pressure from at least one of a runtime flow rate or a downstream pressure and a runtime valve duty cycle. Method 300 can include estimating the runtime supply pressure from at least one of a runtime flow rate or a downstream pressure and a runtime valve duty cycle based on one or more calibration valve duty cycles corresponding to one or more calibration flow rates or downstream pressures and one or more calibration supply pressures. The runtime supply pressure can be estimated by estimating a calibration supply pressure corresponding to a calibration valve duty cycle that is equal to or close to the runtime valve duty cycle. Method 300 can include estimating the runtime supply pressure by controller 130 or electronic pneumatic control module 140. Electronic pneumatic control module 140 can estimate the runtime supply pressure from at least one of a runtime flow rate or a downstream pressure and a runtime valve duty cycle based on one or more calibration valve duty cycles corresponding to one or more calibration supply pressures at one or more calibration flow rates or downstream pressures. The downstream pressure can be a pressure of a gas downstream of valve 205. The downstream pressure can depend on a flow rate, a gas type, a restriction, a pressure, and / or a temperature.

[0046] A population of valves can be measured to determine a curve (e.g., a calibration curve). The calibration curve can be a linear curve, or it can be more complex. Then, at a given electronic pneumatic control module 140 manufacture, measurements can be taken to determine specific values of the curve for the particular electronic pneumatic control module 140. At runtime, the stored calibration values, one or more known curves, and duty cycles at known flow rates can be used to estimate a supply pressure. Method 300 can include characterizing a relationship between valve duty cycles and supply pressures with a parametric equation. The parametric equation can include an equation with parameters that is used to describe a relationship between valve duty cycles and supply pressures at certain flow rates or downstream pressures. The equation can be used to relate a runtime valve duty cycle to a runtime supply pressure at a runtime flow rate or a runtime downstream pressure in order to estimate the runtime supply pressure. Method 300 can include estimating the runtime supply pressure from a calibration table (e.g., a lookup table). The calibration table can include values for supply pressures (e.g., calibration supply pressures), valve duty cycles (e.g., calibration valve duty cycles), and flow rates (e.g., calibration flow rates) or downstream pressures (e.g., calibration downstream pressures). Each valve can have a linear calibration curve with the same slope. The linear calibration curves for the valves can be separated by an offset. The offset can be determined for each valve to calibrate the relationship between supply pressures and duty cycles.

[0047] The estimated runtime supply pressure can be an estimated supply pressure of the source of pressurized gas 110. For example, the estimated runtime supply pressure can be an estimated supply pressure of the source of pressurized gas 110 located at the customer site. The actual runtime supply pressure can be an actual supply pressure of the source of pressurized gas 110. The difference between the actual runtime supply pressure and the estimated runtime supply pressure can be less than 20 psi. For example, the difference between the actual runtime supply pressure and the estimated runtime supply pressure can be less than 20 psi, less than 19 psi, less than 18 psi, less than 17 psi, less than 16 psi, less than 15 psi, less than 14 psi, less than 13 psi, less than 12 psi, less than 11 psi, less than 10 psi, less than 9 psi, less than 8 psi, less than 7 psi, less than 6 psi, less than 5 psi, less than 4 psi, less than 3 psi, less than 2 psi, or less than 1 psi. The actual runtime supply pressure can be greater than or less than the estimated runtime supply pressure by less than 20 psi, less than 19 psi, less than 18 psi, less than 17 psi, less than 16 psi, less than 15 psi, less than 14 psi, less than 13 psi, less than 12 psi, less than 11 psi, less than 10 psi, less than 9 psi, less than 8 psi, less than 7 psi, less than 6 psi, less than 5 psi, less than 4 psi, less than 3 psi, less than 2 psi, or less than 1 psi. For actual supply pressures in the range of 80 psi to 170 psi, the difference between the actual runtime supply pressure and the estimated runtime supply pressure can be less than 5 psi. For actual supply pressures in the range of 150 psi to 175 psi, the difference between the actual runtime supply pressure and the estimated runtime supply pressure can be less than 7 psi. The method 300 can include estimating the runtime supply pressure by the controller 130 or the electronic pneumatic control module 140. The method 300 can include estimating the actual supply pressure without directly measuring the actual supply pressure (e.g., with a sensor).

[0048] The method 300 can include determining that the runtime supply pressure is greater than a threshold supply pressure value (block 320). For example, the method 300 can include determining that the runtime supply pressure is greater than a threshold supply pressure value. The method 300 can include determining that the runtime supply pressure is less than a threshold supply pressure value. The method 300 can include determining that the runtime supply pressure is equal to a threshold supply pressure value. The method 300 can include determining that the threshold supply pressure value is greater than, less than, or equal to the runtime supply pressure. The method can include determining, by the controller 130 or the electronic pneumatic control module 140, that the runtime supply pressure is greater than, less than, or equal to the threshold supply pressure value.

[0049] The threshold supply pressure value can be in a range of 130 psi to 200 psi. For example, the threshold supply pressure value can be in a range of 130 psi to 135 psi, 130 psi to 140 psi, 130 psi to 145 psi, 130 psi to 150 psi, 130 psi to 155 psi, 130 psi to 160 psi, 130 psi to 165 psi, 130 psi to 170 psi, 130 psi to 175 psi, 130 psi to 180 psi, 130 psi to 185 psi, 130 psi to 190 psi, 130 psi to 200 psi, 135 psi to 140 psi, 135 psi to 145 psi, 135 psi to 150 psi, 135 psi to 155 psi, 135 psi to 160 psi, 135 psi to 165 psi, 135 psi to 170 psi, 135 psi to 175 psi, 135 psi to 180 psi, 135 psi to 185 psi, 135 psi to 190 psi, 135 psi to 200 psi, 140 psi to 145 psi, 140 psi to 150 psi, 140 psi to 155 psi, 140 psi to 160 psi, 140 psi to 165 psi, 140 psi to 170 psi, 140 psi to 175 psi, 140 psi to 180 psi, 140 psi to 185 psi, 140 psi to 190 psi, 140 psi to 200 psi, 145 psi to 150 psi, 145 psi to 155 psi, 145 psi to 160 psi, 145 psi to 165 psi, 145 psi to 170 psi, 145 psi to 175 psi, 145 psi to 180 psi, 145 psi to 185 psi, 145 psi to 190 psi, or 145 psi to 200 psi.

[0050] The threshold supply pressure value can be in a range of 150 psi to 175 psi. For example, the threshold supply pressure value can be in a range of 150 psi to 155 psi, 150 psi to 160 psi, 150 psi to 165 psi, 150 psi to 170 psi, 150 psi to 175 psi, 155 psi to 160 psi, 155 psi to 165 psi, 155 psi to 170 psi, 155 psi to 175 psi, 160 psi to 165 psi, 160 psi to 170 psi, 160 psi to 175 psi, 165 psi to 170 psi, 165 psi to 175 psi, or 170 psi to 175 psi.

[0051] The method 300 can include generating (e.g., providing, producing) a notification (block 325). For example, the method 300 can include generating a notification in response to the runtime supply pressure being greater than the threshold supply pressure value. The method 300 can include generating a notification that the runtime supply pressure is greater than the threshold supply pressure value in response to determining that the runtime supply pressure is greater than the threshold supply pressure value. The notification can include a notification that the runtime supply pressure is greater than the threshold supply pressure value.

[0052] The method 300 can include generating a notification in response to the runtime supply pressure being less than the threshold supply pressure value. For example, the method 300 can include generating a notification that the GC system 100 passed one or more diagnostic tests in response to the runtime supply pressure being less than the threshold supply pressure value. The notification can include a notification that the runtime supply pressure is less than the threshold supply pressure value. The method 300 can not include generating a notification for a passing result if the GC system 100 is undergoing continuous monitoring. The method 300 can include generating a notification that the runtime supply pressure is less than the threshold supply pressure value in response to determining that the runtime supply pressure is less than the threshold supply pressure value. The method 300 can include not generating a notification in response to the runtime supply pressure being less than the threshold supply pressure value.

[0053] The method 300 can include generating a notification in response to the runtime supply pressure being equal to the threshold supply pressure value. The notification can include a notification that the runtime supply pressure is equal to the threshold supply pressure value. The method 300 can include generating a notification that the runtime supply pressure is equal to the threshold supply pressure value in response to determining that the runtime supply pressure is equal to the threshold supply pressure value. The method 300 can include not generating a notification in response to the runtime supply pressure being equal to the threshold supply pressure value.

[0054] The GC system 100 or the electronic pneumatic control module 140 can generate a notification. The method 300 can include generating the notification in response to the estimated supply pressure being greater than a threshold supply pressure value. The method 300 can include generating the notification in response to the estimated supply pressure being less than or equal to the threshold supply pressure value. The method 300 can include generating the notification in response to a difference between the estimated supply pressure and the threshold supply pressure value being greater than a threshold difference value. The notification can alert a user that the actual supply pressure is likely greater than a specification. The threshold supply pressure value can be higher than a specified pressure for the GC system 100. The threshold supply pressure value can be higher than the specified pressure such that the notification is not generated when the estimated supply pressure is less than the specified pressure. If the runtime supply pressure is greater than the threshold supply pressure value and the configured gas is H2, an H2 shutdown can be caused. The H2 shutdown can shut down all heating zones. The method 300 can include shutting down one or more heating zones (e.g., for H2) in response to the runtime supply pressure being greater than the threshold supply pressure value.

[0055] The method 300 can include generating a notification. The notification can include at least one of a light, a message, a beep, a text, or an email. The notification can alert a user of the GC system 100 that the actual supply pressure is out of specification, outside of specification, or that the pressure is too high. For example, the notification can alert the user that components upstream of the valve 205 are not working as expected. For example, the notification can alert the user that one or more regulators upstream of the valve 205 can not be working. The notification can alert the user that components upstream of the valve 205 are operating outside of specification. The notification can include displaying a message on a display of the GC system 100. The notification can include sending a text or an email. The notification can include setting or changing a color of a status light. The notification can include providing an audio notification (e.g., providing a beep). The notification can appear or be displayed in a browser (e.g., web browser) interface for the GC system 100. The notification can appear or be displayed in a data system interface.

[0056] Further operations of the GC system 100 can be stopped (e.g., paused, aborted) in response to the runtime supply pressure being greater than the threshold supply pressure value. The method 300 can include generating a notification by the controller 130 or the electronic pneumatic control module 140 if the runtime supply pressure is greater than the threshold pressure. If the GC system 100 is running hydrogen, the column heater 125 can be disabled in response to the runtime supply pressure being greater than the threshold supply pressure value.

[0057] The method 300 can include continuing GC system operation if the runtime supply pressure is not greater than the threshold supply pressure value. For example, the method 300 can include continuing GC system operation if the estimated supply pressure is not greater than the threshold supply pressure value. The method 300 can include continuing GC system operation if the estimated supply pressure is less than the threshold supply pressure value. If the threshold pressure is greater than the estimated supply pressure, the GC system 100 can continue to operate without generating a notification. The method 300 can include continuing operation of the GC system 100 if the runtime supply pressure is not greater than the threshold supply pressure value.

[0058] Calibration can be performed at various flow rates or downstream pressures, as the gas channel can be set to various flow rates or downstream pressures during use by a user or the GC system 100. If there is continuous monitoring of the supply pressure during operation of the GC system 100 (e.g., during GC analysis or when the system is idle between analyses), calibration can account for different flow rates or downstream pressures.

[0059] The valve 205 can be calibrated at different supply pressures at a single flow rate. During runtime, a diagnostic procedure can be implemented in which the GC system 100 can be in a state dedicated to estimating the supply pressure. For example, the diagnostic procedure can be implemented during initial installation, during start-up, or during any other selected time. During the diagnostic procedure, the GC system 100 can set the flow rate or downstream pressure to the flow rate or downstream pressure used in the calibration process. When the GC system 100 completes estimating the supply pressure, the flow rate can then be changed to a different value for analysis. The estimation process need not use a flow rate, as there can only be one flow rate for that particular valve. The diagnostic procedure can be run by a user selecting to run the diagnostic procedure, for example, by pressing or clicking a button to start the diagnostic procedure. The GC system 100 can automatically and / or continuously run the diagnostic procedure when the GC system 100 is turned on, starts a troubleshooting procedure, or is idle between runs. The GC system 100 can run the diagnostic procedure during any opportunity that the flow rate can be changed to the calibration flow rate and not interfere with the work the instrument is doing. The GC system 100 can run the diagnostic procedure at a user-specified flow rate or downstream pressure. In this case, the GC system 100 can be calibrated for the user-specified flow rate, each of one or more downstream pressures. The method 300 can include implementing a diagnostic procedure. For example, the method 300 can include implementing a diagnostic procedure at a specified flow rate (e.g., a single selected flow rate).

[0060] In some embodiments, the diagnostic procedure can run as a user initiated action outside of the normal workflow. In this setup, the GC system 100 can specify a known flow rate. Thus, calibration information for one flow rate can be stored in the EEPROM. The user or the GC system 100 can set a flow rate set point. The GC system 100 can use this flow rate set point, gas type, temperature, and restrictor parameters to calculate a downstream pressure set point. When the GC system 100 has this downstream pressure set point, the GC system 100 can use the valve 205 to control this set point and give a valve duty cycle. Thus, instead of using the flow rate directly to estimate the supply pressure, this flow rate set point can be converted to a downstream pressure set point and can be used (along with using the valve duty cycle) to calibrate and estimate the supply pressure. This can decouple the calibration and estimation process from the gas type being used, as it is calculated out when converting from flow rate to downstream pressure. In this case, for those channels that can be connected to different types of supply gas, it can not be necessary to know the configured gas or to calibrate for multiple gases.

[0061] The method 300 can be used for an electronic pneumatic control module 140 attached to an injection port 105 or inlet. The method 300 can be used for an electronic pneumatic control module 140 attached to a detector 120. The method 300 can be used for an electronic pneumatic control module 140 supplying gas to a pneumatic switching device (e.g., an active detector splitter, a backflush device, a Deans switch, etc.) and / or an autosampler (e.g., a headspace device or a gas sampling valve).

[0062] Figure 4 is a plot 400 of valve duty cycle (%) versus supply pressure (psi). The duty cycle can include a calibrated valve duty cycle for a specified gas at a specified flow rate. The supply pressure can include a calibrated supply pressure. The duty cycle (e.g., valve duty cycle) can be defined as the extent to which the valve 205 is opened or closed to provide a certain flow rate. The valve duty cycle can depend on the set points (e.g., flow rate set point) of the supply pressure and flow rate. The flow rate set point can include a calibrated flow rate. The duty cycle needed to achieve a 30 mL / min flow rate of H2 gas for a known supply pressure can be plotted against the known supply pressure of the gas. The duty cycle needed to achieve a 30 mL / min flow rate of H2 gas for a known pressure can have a roughly linear relationship over a specified operating range of the valve 205. Above a threshold, the relationship between supply pressure and valve duty cycle can no longer be linear. If the pressurized gas source pressure is higher, the valve duty cycle can be lower (e.g., the valve 205 is opened less). Valve A, Valve B, and Valve C all behave similarly in terms of the curve shape and can be characterized by a parametric function over a specified pressure window.

[0063] Embodiments of the subject matter and operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. The subject matter described in this specification can be implemented as one or more computer programs, e.g., one or more circuits of computer program instructions, encoded on one or more computer storage media for execution by, or to control the operation of, data processing apparatus. Alternatively or additionally, the program instructions can be encoded as propagated signals - e.g., machine-generated electrical, optical, or electromagnetic signals - that are generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or include, one or more of volatile memory, non-volatile memory, or a combination of one or more of them. In addition, where a computer storage medium is not a propagated signal, the computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be, or include, one or more separate components or media (e.g., multiple CDs, disks, or other storage devices). The operations described in this specification can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

[0064] The operations described in this specification can be implemented by a data processing apparatus executing instructions stored on one or more computer-readable storage devices or received from other sources. The term“data processing apparatus” or“computing device” encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones of the foregoing. The apparatus can include special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). The apparatus can also include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them. The apparatus and execution environment can realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures.

[0065] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a circuit, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more circuits, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and are interconnected by a communication network.

[0066] By way of example, a processor suitable for executing a computer program includes the microprocessor, and the like, and any one or more processors of a digital computer. A processor can receive instructions and data from a read-only memory or a random access memory or both. The elements of a computer are a processor for performing actions in accordance with instructions and one or more memory devices for storing instructions and data. A computer can include, or be operatively coupled to, one or more mass storage devices (e.g., magnetic, magneto-optical or optical disks) for storing data. A computer need not have such devices. In addition, a computer can be embedded in another device, e.g., a personal digital assistant (PDA), a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks (e.g., internal hard disks or removable disks); magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0067] To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0068] Implementations of the subject matter described in this specification can be implemented in any of various ways. For example, the implementations can be implemented using hardware, software, or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers.

[0069] Also, a computer can have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for providing visual presentation of output and speakers or other sound generating devices for providing audible presentation of output. One specific example is a computer that has a screen that presents a user interface, and a keyboard and mouse that allow a user to interact with the user interface. Another specific example is a computer that presents a user interface through a web browser, and receives input through a webcam or other input device.

[0070] Such computers can be interconnected by one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks can be based on any suitable technology and can operate according to any suitable protocol and can include wireless networks, wired networks or fiber optic networks.

[0071] A computer for implementing at least part of the functionality described herein can include a memory, one or more processing units (also referred to herein simply as “processors”), one or more communication interfaces, one or more display units, and one or more user input devices. The memory can include any computer-readable medium and can store computer instructions (also referred to herein as “processor-executable instructions”) for implementing the various functionality described herein. The one or more processing units can be used to execute the instructions. The one or more communication interfaces can be coupled to a wired or wireless network, bus, or other communication device and thus can allow the computer to transmit communications to or receive communications from other devices. The one or more display units can be provided, for example, to allow a user to view various information related to the execution of the instructions. The one or more user input devices can be provided, for example, to allow the user to make manual adjustments during execution of the instructions, make selections, input data or various other information, or interact with the processor in any of various ways.

[0072] The various methods or processes outlined herein can be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software can be written using any of a number of suitable programming languages or programming or scripting tools, and also can be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine.

[0073] In this respect, various inventive concepts can be embodied as a computer readable storage medium (or multiple computer readable storage media) (e.g., a computer memory, one or more floppy discs, compact discs, optical discs, magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other non-transitory medium or tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments of the solution discussed above. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various aspects of the present solution as discussed above.

[0074] The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects as discussed above. When a program or programs are executed, they can need not reside on a single computer or processor, but can be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present solution.

[0075] Computer-executable instructions can be in many forms, such as program modules, executed by one or more computers or other devices. A program module can include routines, programs, objects, components, data structures, or other components that perform particular tasks or implement particular abstract data types. The functionality of the program modules can be combined or distributed as desired in various embodiments.

[0076] Also, data structures can be stored in computer-readable media in any suitable form, for ease of explanation, data structures can be shown to have fields that are related through location in the data structure. Such relationships can likewise be achieved by assigning storage for the fields with locations that convey the relationship among the fields. However, any suitable mechanism can be used to establish a relationship among information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish a relationship between data elements.

[0077] Any reference to implementations or elements or acts of a system and method, in the singular, can include one or more implementations including a combination of the referenced item(s) or a combination of one or more implementations of the referenced item(s). Any reference to any implementation or element or act of any implementation, in the plural, can include one or more implementations of the referenced item or a combination of one or more implementations of the referenced item.

[0078] Any implementation disclosed herein can be combined with any other implementation and the reference to an “implementation,” “some implementations,” “alternative implementations,” “various implementations,” “one implementation,” etc., is not necessarily mutually exclusive, and is intended to indicate that a particular feature, structure, or characteristic described in connection with the implementation can be included in at least one implementation. Such terms as used herein are not necessarily all referring to the same implementation. Any implementation can be exclusively combined with any other implementation or implementations disclosed herein, inclusively or exclusively, with any other implementation or implementations.

[0079] A reference to “or” can be construed as inclusive so that any term described using “or” can indicate a single, more than one, and all of the described terms. A reference to at least one of something listed can be construed as a non-exclusive OR so that any of the listed items can be included, individually, more than one of the listed items, and all of the listed items. For example, a reference to “at least one of ‘A’ and ‘B’” can include only ‘A’, only ‘B’, as well as both ‘A’ and ‘B’. It can also include an element other than ‘A’ and ‘B’.

[0080] The systems and methods described herein can be embodied in other specific forms without departing from the characteristics thereof. The foregoing implementations are illustrative rather than limiting, and the described systems and methods are not limited to the foregoing implementations.

[0081] Where a technical feature is followed in the drawings, detailed description or any claim by a reference sign, the reference sign has been included to increase the intelligibility of the drawings, detailed description and claims. Thus, the presence or absence of the reference sign does not have any limiting effect on the scope of any claim element.

[0082] The systems and methods described herein can be embodied in other specific forms without departing from the characteristics thereof. The foregoing implementations are illustrative rather than limiting, and the described systems and methods are not limited to the foregoing implementations. The scope of the systems and methods described herein is thus indicated by the appended claims, rather than by the foregoing description, and changes that come within the meaning and range of equivalents of the claims are intended to be embraced therein.

Claims

1. A method for estimating the gas supply pressure of a gas chromatography (GC) system, the method comprising: Measure the valve duty cycle of the valves in the GC system during operation; The operating supply pressure is estimated from at least one of the operating flow rate or the downstream pressure and the operating valve duty cycle, based on one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. as well as In response to determining that the runtime supply pressure is greater than a threshold supply pressure value, a notification is generated that the runtime supply pressure is greater than the threshold supply pressure value.

2. The method of claim 1, further comprising determining that the runtime supply pressure is less than or equal to the threshold supply pressure value.

3. The method of claim 2, further comprising generating a notification that the runtime supply pressure is less than or equal to the threshold supply pressure value.

4. The method of claim 1, further comprising measuring the duty cycle of the one or more calibration valves corresponding to the one or more calibration supply pressures and the one or more calibration flow rates or the downstream pressure.

5. The method of claim 1, further comprising storing each of the one or more calibration valve duty cycles corresponding to a corresponding calibration supply pressure among the one or more calibration supply pressures and a corresponding calibration flow rate among the one or more calibration flow rates or the downstream pressure in the electronic pneumatic control module (EEPROM) of the GC system.

6. The method according to claim 1, wherein: The operating supply pressure is the estimated supply pressure; and The difference between the actual supply pressure and the estimated supply pressure is less than 20 psi.

7. The method according to claim 1, wherein, The valve is located in the electronic pneumatic control module of the GC system.

8. The method according to claim 1, wherein, The valve is located upstream of the injection port of the GC system.

9. The method according to claim 1, wherein, The valve is located upstream of the detector of the GC system.

10. The method of claim 1, further comprising estimating the runtime supply pressure from a calibration table.

11. The method of claim 1, further comprising characterizing the relationship between the valve duty cycle and the supply pressure using a parameterized equation.

12. The method according to claim 1, wherein, The valve is fluidly coupled to the pressurized gas source.

13. The method of claim 1, further comprising performing the diagnostic procedure at a specified flow rate or the downstream pressure.

14. The method according to claim 1, wherein, The threshold supply pressure value is in the range of 130 psi to 200 psi.

15. The method of claim 1, further comprising measuring each of the one or more calibration valve duty cycles required to achieve the target flow rate or target downstream pressure at the corresponding calibration supply pressure among the one or more calibration supply pressures.

16. The method of claim 1, further comprising shutting down one or more heating zones in response to the runtime supply pressure being greater than the threshold supply pressure value.

17. The method according to claim 1, wherein, A pressure sensor is located downstream of the valve.

18. The method according to claim 1, wherein, The notification includes at least one of light, message, beep, text, or email.

19. A gas chromatography (GC) system, comprising: valve; as well as The electronic pneumatic control module is configured to: Measure the valve duty cycle during operation; The operating supply pressure is estimated from at least one of the operating flow rate or the downstream pressure and the operating valve duty cycle, based on one or more calibration supply pressures and one or more calibration flow rates or downstream pressures. and In response to determining that the runtime supply pressure is greater than a threshold supply pressure value, a notification is generated that the runtime supply pressure is greater than the threshold supply pressure value.

20. The GC system according to claim 19, wherein, The electronic pneumatic control module further includes an EEPROM configured to store each of the one or more calibration valve duty cycles corresponding to a corresponding calibration supply pressure in the one or more calibration supply pressures and a corresponding calibration flow rate in the one or more calibration flow rates or the downstream pressure.

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