A method for calculating the time utilization of a gas chromatograph mass spectrometer

Abstract

The application discloses a method for calculating the time utilization rate of a gas chromatograph-mass spectrometer, which collects the working current of the gas chromatograph or the mass spectrometer or the gas chromatograph and the mass spectrometer to obtain current spectrum, identifies the start and end time of respective test states through an algorithm, determines the actual working time of the combined instrument, and calculates the time utilization rate. The application verifies the feasibility of determining the working state of the combined instrument through the working current of a single device and calculating the utilization rate, solves the automatic collection of the working state of key detection equipment in a laboratory, helps enterprises to understand the operation law and trend of the equipment, provides a scientific basis for production planning and resource allocation of the enterprises, and has a significant application value.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of equipment working state acquisition and operation rate statistics, and particularly relates to a method for calculating the time operation rate of a gas chromatograph mass spectrometer (GCMS). BACKGROUND

[0002] In today's rapidly developing manufacturing environment, enterprises have increasingly high requirements for production efficiency and management efficiency. As one of the important indicators for measuring the production efficiency of an enterprise, the equipment operation rate directly reflects the resource utilization efficiency and production capacity of the enterprise. The operation rate refers to the proportion of the time occupied by the equipment for creating value in the time it can provide. The traditional equipment operation rate statistical method usually relies on manual recording and periodic summary, and this method has many limitations, such as low efficiency, poor data accuracy, susceptibility to human factors, high labor cost, etc.

[0003] Regarding the automatic statistical method of the operation rate, the following prior art is found through retrieval:

[0004] I. The Chinese patent application with the publication number CN112784217A and the invention name of "industrial equipment operation rate statistical method, device, computer equipment and storage medium" discloses an industrial equipment operation rate statistical method. According to the acquired equipment current energy consumption data of the equipment to be tested, the current actual running condition of the equipment to be tested is determined based on the pre-set standard current upper limit and standard current lower limit, and the current equipment real-time operation rate is calculated based on the pre-set standard processing cycle according to the determined current actual running condition.

[0005] II. The Chinese patent application with the publication number CN104808587A and the invention name of "operation rate statistical method based on the running state of a machining equipment" also discloses an operation rate statistical method. The running state of the machining equipment is identified based on a power characteristic model combined with a KNN classification algorithm, and the start and end times of each running state are recorded. The time parameters are calculated, and thus the time operation rate and performance operation rate of the machining equipment are calculated.

[0006] For the above-mentioned prior art I, the equipment current data is collected and the equipment is determined to be working or not by the current threshold. This method cannot cover all equipment conditions, and some equipment cannot be determined to be working or not by a simple current threshold. For example, the gas chromatograph mass spectrometer in the TIC industry chemical detection field often involves equipment, and the current of the equipment when working is a regular characteristic curve, and some current values will be in the standby current interval. Therefore, the working time of the equipment cannot be determined by the method of the above-mentioned prior art I.

[0007] For the above-mentioned prior art two, based on the power characteristic model combined with KNN classification algorithm to identify the running state of the processing equipment, it is aimed at a single equipment, the collection object is the total input power of the equipment, and a specific power characteristic model needs to be trained for each manufacturer and each different model of equipment.

[0008] And for the gas chromatograph mass spectrometer (GCMS) of the application, on the one hand, it is a device composed of two instruments working together, including a gas chromatograph and a mass spectrometer, on the other hand, a GCMS can flexibly configure multiple analysis methods, covering the parameter settings of the gas chromatograph (GC) and the mass spectrometer (MS), theoretically, a GCMS can configure thousands of test analysis methods, under different analysis methods, such as the starting temperature of the column oven, the inlet temperature, the transmission line temperature and the ion source temperature, and when switching analysis methods, a long waiting time is often needed to let the state of the equipment reach stability, which brings difficulties to the application of the above-mentioned prior art two method to calculate the GCMS uptime. SUMMARY

[0009] The purpose of the application is to provide a method for calculating the time uptime of a gas chromatograph mass spectrometer.

[0010] The purpose of the application is achieved by the following technical solution: a method for calculating the time uptime of a gas chromatograph mass spectrometer, the gas chromatograph mass spectrometer comprising a gas chromatograph and a mass spectrometer, characterized in that the method adopts any of the following schemes:

[0011] Scheme one: collect the working current of the gas chromatograph to obtain its current spectrum, identify the start and end time of its test state by algorithm, and determine the actual working time of the combined instrument, and then calculate the time uptime, unless the gas chromatograph ends the test state before the mass spectrometer, in which case, the test analysis time period T of the gas chromatograph and the mass spectrometer acquisition time recorded in the control software of the combined instrument are corrected to calculate the time uptime; the mass spectrometer acquisition time refers to the actual working time of the mass spectrometer compared to the T;

[0012] Scheme two: collect the working current of the mass spectrometer to obtain its current spectrum, identify the start and end time of its test state by algorithm, and determine the actual working time of the combined instrument, and then correct the test analysis time period T of the gas chromatograph and the mass spectrometer acquisition time recorded in the control software of the combined instrument to calculate the time uptime; the mass spectrometer acquisition time refers to the actual working time of the mass spectrometer compared to the T;

[0013] Scheme three: the working current of the gas chromatograph and the mass spectrometer is collected to obtain the current spectrum thereof, the starting and ending time of each test state is identified through an algorithm, and the actual working time of the combined instrument is jointly determined and the time utilization rate thereof is calculated.

[0014] Experiments prove that the current information of the gas chromatograph or the mass spectrometer can clearly depict the state change trend of the GCMS during operation, and it is effective and reliable to monitor the running state and change of the combined instrument through the current collection data of the instrument alone.

[0015] In addition, it is found through research that, generally, the gas chromatograph enters the test state earlier than the mass spectrometer, and ends the test state together with the mass spectrometer or lags behind the mass spectrometer to end the test state, and the instruments of some manufacturers can be set to end the test state earlier than the mass spectrometer, based on the above different situations, the actual working time of the combined instrument can be determined jointly according to the starting and ending time of the test state of the gas chromatograph and the mass spectrometer, or the starting and ending time of the test state of the gas chromatograph or the mass spectrometer alone can be used to determine, only in this case, a correction parameter is introduced to correct the result when necessary.

[0016] Generally, the starting and ending time of the test state of each instrument can be well identified through the current data of the gas chromatograph and the mass spectrometer, so the joint determination method can save the consideration of correction, if only the data of a single instrument is selected, since the current change of the gas chromatograph in different working states is more obvious, it is more recommended to select the current spectrum thereof to identify the working state, and for the case that the current spectrum change of the chromatograph in some test analysis methods is not obvious, the current spectrum of the mass spectrometer can be used for analysis and determination.

[0017] The data acquisition module is used to collect the working current, in order not to damage the existing laboratory circuit structure, the data acquisition module used in the application comprises a row plug, the power output ports of the row plug are connected to the power input ports thereof through wires respectively, the data acquisition module further comprises a data collector and a plurality of (two or more) current transformers, the current transformers are tapped on each parallel branch for collecting the current on each parallel branch and outputting to the data collector.

[0018] By using the data acquisition module of the application, the working current data of the gas chromatograph and the mass spectrometer can be collected only by normally plugging the two instruments into the sockets of the row plug, which greatly reduces the cost of modifying the existing laboratory circuit for collecting the working current of the equipment, and does not damage the power supply circuit of the precise instruments such as the gas chromatograph and the mass spectrometer, thereby reducing the influence on the running state of the equipment, and the application has strong reliability.

[0019] The structure of the communication system based on the method of the application is as follows:

[0020] Using the Modbus RTU communication protocol, the server sends collection instructions to the data collector at the terminal position through the LoRa communication gateway and the wireless LoRa communication module, controls the collector to collect the respective working current data of the gas chromatograph and the mass spectrometer, and the server analyzes and processes the current data graph collected and calculates the actual working time of the combined instrument and the time utilization rate thereof.

[0021] The above algorithm can adopt a machine learning algorithm, such as a KNN classification algorithm, a CNN algorithm, etc., but it inevitably needs a large number of training samples and a long training period, and the following is an improved scheme:

[0022] The application adopts the following algorithm to identify the start and end time of the test state of the gas chromatograph and mass spectrometer:

[0023] Step 1) According to the current trend change characteristics of the configured test analysis method, define the test start current threshold I1, the start determination current threshold I2, the duration coefficient n, the difference determination value D, the test end determination current I3 and the end current threshold I4, obtain the current collection frequency F, and the test analysis time period T of the gas chromatograph set in the instrument control software; here I3<I4≦I1<I2;

[0024] Step 2) Instrument start working time point determination

[0025] When the working current of the instrument exceeds I1, the current time point is recorded as a to-be-effective state, and whether it is effective is determined;

[0026] Read the working current for a time period T, and when the working current of the instrument exceeds I2 for more than three times and the interval time between the first time and the last time is greater than nT, it is determined that the above-mentioned recorded time point is effective and is stored as the instrument start working time point, otherwise, the above-mentioned buffered recorded time point is cleared;

[0027] Step 3) Instrument end working time point determination

[0028] After determining that the instrument enters the test state, when the working current of the instrument is less than I3, the last collected current value is subtracted from the current current value, and if the change is significant and the difference is greater than D, the current time point is recorded as a to-be-effective state, and whether it is effective is determined;

[0029] Read the working current for a time period T, and when the working current of the instrument is less than I4 within the time period T, it is determined that this time point is effective and is stored as the instrument end working time point, otherwise, the buffered recorded time point is cleared.

[0030] Beneficial effects:

[0031] 1) The application verifies the feasibility of determining the working state of the combined instrument by the working current of a single device and calculating the time utilization rate, solves the automatic collection of the working state of the key detection device in the laboratory, helps the enterprise to understand the operation rules and trends of the device, provides a scientific basis for the production plan and resource allocation of the enterprise, and has significant application value;

[0032] 2) The current data collection method of the application only needs to normally plug the gas chromatograph and mass spectrometer into the outlets of the extension socket, so that the working current data of each device can be collected, which greatly reduces the modification cost of the existing laboratory circuit for collecting the working current of the device, and does not need to damage the power supply circuit of the precision instruments such as gas chromatograph and mass spectrometer, which can reduce the influence on the running state of the device, and has strong application reliability;

[0033] 3) For GCMS devices, the application designs a unified algorithm, only needs to collect a round of current data of the GCMS device for a short time to analyze the current curve characteristics, obtains several related parameters that meet the characteristics of the device and the test analysis method, so that each device can call the algorithm with specific parameters to determine the start and end time of the test, which not only ensures the accuracy of determining the working state of the device, but also can be quickly reused, greatly shortening the time cost. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The structure schematic diagram of the communication system based on which the time utilization rate statistical method of the embodiment is based on;

[0035] Figure 2 The structure composition schematic diagram of the data collection module used in the embodiment;

[0036] Figure 3 The current data characteristics of the four different running states of GCMS;

[0037] Figure 4 The current data of GCMS when running method A (analysis method of o-benzene in toy materials), the blue curve is GC, and the red curve is MS;

[0038] Figure 5 The current data of GCMS when running test analysis method B, the blue curve is GC, and the red curve is MS;

[0039] Figure 6 The current data of GCMS when running test analysis method C, the blue curve is GC, and the red curve is MS. DETAILED DESCRIPTION

[0040] The embodiment calculates the time utilization rate of the gas chromatograph-mass spectrometer combined instrument by the following method:

[0041] Figure 1 The structure diagram of the communication system based on which the time utilization rate statistical method of the embodiment is based is shown in the figure:

[0042] By using the Modbus RTU communication protocol, the server sends a collection instruction to the data collector at the terminal position through the LoRa communication gateway and the wireless LoRa communication module, controls the collector to collect the working current data of the gas chromatograph and the mass spectrometer respectively, and then the server analyzes and processes the collected current data and determines the working state of the GC-MS, especially identifies the start and end time of the test state, and finally calculates the time utilization rate of the GC-MS. The test proves that the current information of GC and MS obtained can clearly depict the state change trend of GCMS when running, which shows that monitoring the running state and change of the GC-MS through the current collection data of the instrument is effective and reliable.

[0043] In order not to damage the existing laboratory circuit structure, the data collection module structure adopted by the embodiment is shown in Figure 2 It includes a row plug, the row plug includes a shell, a power input port and two power output ports arranged on the shell, the two power output ports are connected to the power input port through wires respectively, the data collection module further includes a data collector and two current transformers, the two current transformers are respectively used to collect the current on the two parallel branches and output to the data collector.

[0044] By using the data collection module of the embodiment, the working current data of GC and MS can be collected only by normally plugging the devices into the sockets of the row plug, which greatly reduces the cost of modifying the existing laboratory circuit for collecting the working current of the devices, and does not need to damage the power supply circuit of the precise instruments such as GC and MS, which can reduce the influence on the running state of the devices and has strong application reliability.

[0045] Regarding the problem of representing the start and end time of the test state of the GC-MS:

[0046] It is found through research that generally, the gas chromatograph enters the test state earlier than the mass spectrometer, and ends the test state together with the mass spectrometer or lags behind the mass spectrometer to end the test state, and some instruments of some manufacturers can set the gas chromatograph to end the test state earlier than the mass spectrometer.

[0047] That is, the start and end time of the test state of the gas chromatograph can usually directly represent the actual working time of the combined instrument, unless the gas chromatograph ends the test state before the mass spectrometer. The start and end time of the test state of the mass spectrometer usually cannot directly represent the actual working time of the combined instrument. The reason why they cannot "directly" represent is that there is a parameter in the instrument control software: the mass spectrometry acquisition time, which reflects the actual test time of the mass spectrometer compared to the test and analysis time period of the gas chromatograph. As can be seen, this data can be used to correct the above-mentioned situations that cannot directly reflect the actual working time of the combined instrument, so that the start and end time monitored by them can be used. Of course, the method of taking the union of the start and end time of the test state identified by the current map of the gas chromatograph and the current map of the mass spectrometer can also be used, and users can choose according to the actual application scene. For example, usually, the current of the gas chromatograph changes more obviously in different working states, so it is recommended to use its current map to identify the working state first. For the case where the current map of the chromatograph does not change obviously in some test and analysis methods, the current map of the mass spectrometer can be used for analysis and determination. If there is no special situation, that is, the current map of the gas chromatograph and the current map of the mass spectrometer can be used to identify the working state, and you do not want to consider the correction problem, the identification results of the two can be used for joint determination.

[0048] As can be seen from the above, we can analyze the current map of each of the two devices to identify the start and end time of the test state of the combined instrument, such as through a machine learning algorithm such as a trained KNN classification algorithm or a CNN algorithm. However, according to the background art part, a large number of training samples and a long training period are required.

[0049] To solve this problem, the applicant has made the following research: The parameters that need to be loaded for the gas chromatograph-mass spectrometer combined instrument include the initial column oven temperature, the sample inlet temperature, the flow rate, the transfer line temperature, the ion source temperature, etc. The working process thereof generally includes the following steps:

[0050] S1: The gas chromatograph and the mass spectrometer load the initial parameters of the analysis method

[0051] If the initial parameters of the analysis method this time are different from the parameters of the original analysis method loaded on the instrument, the chromatograph-mass spectrometer will start the corresponding module to adjust the instrument to meet the new parameter loading requirements, mainly enabling the functions of heating and cooling, etc.

[0052] S2: After the initial parameter loading process of the instrument analysis method is completed, the gas chromatograph mass spectrometer enters the device ready state, at this time the power value is related to the performance of the device itself and the initial parameters of the loaded analysis method, and the power fluctuates up and down within a certain range. Then, the automatic sampler of the gas chromatograph starts, the transmission motor starts, the mechanical arm starts to rotate to grab the sample bottle, the sampling needle starts to clean and sample, after the sample is punched into the sampling port of the gas chromatograph by the sampler, the gas chromatograph and mass spectrometer receive the sampling signal and start running the test method.

[0053] S3: After the analysis method is completed, the column temperature of the gas chromatograph is cooled and the flow rate is restored to the initial state, and the filament, quadrupole rod and detector of the mass spectrometer also enter the device ready state.

[0054] The above process usually corresponds to the initial state, standby, sampling, analysis, recovery of the initial state, standby, etc. of the instrument analysis method loaded by the combined instrument, and the current trend curves of the two instruments reflect their respective power characteristics and energy consumption characteristics in different states, and are finally divided into four running states, including shutdown state, standby state, device ready state and test state, as shown in Figure 3 , wherein the yellow square represents the shutdown state (executing shutdown or having been shut down), the blue square represents the device ready state, the orange square represents the test state, and the green square represents the standby state.

[0055] After a large number of observations and experiments, it is found that the working current of each of the two devices of the combined instrument has the following variation law:

[0056] Except for power-on, loading instrument analysis method, entering test state, executing shutdown, the current curve will have certain fluctuations, and the amplitude and duration of the fluctuations are significantly different, and the current will fluctuate stably within a certain current range at other times such as standby state and device ready state, and the current value is staggered with the current value at the beginning of entering the test state. When the device enters the test state, i.e. executes the analysis method for testing, the current spectrum will change periodically, and the length of the period and the number of period changes are related to the settings of the instrument control software, and are accurate. In other words, they are consistent. In addition, during the test state, the current value will change significantly in a short time when the device starts working and ends working.

[0057] Based on the above findings, the applicant summarizes the following method to identify the starting point and ending point of the test state of the gas chromatograph and mass spectrometer:

[0058] Step 1) defining the test start current threshold I1, the start judgment current threshold I2, the duration coefficient n, the difference judgment value D, the test end judgment current I3 and the end current threshold I4 according to the current trend change characteristics of each test analysis method, obtaining the acquisition frequency F of the current of the device, and setting the test analysis time period T of the GC in the device control software; here I3 < I4 < I1 < I2;

[0059] Step 2) instrument start working time point judgment

[0060] When the acquisition current of the instrument, i.e. its working current, exceeds I1, the current time point is recorded as a to-be-effective state, and whether it is effective is judged;

[0061] The working current of a time period T is read, and when the instrument working current exceeds I2 for more than three times and the interval time between the first time and the last time is greater than nT (obviously, n is less than or equal to 1), it is determined that the above-mentioned recorded time point is effective and is stored as the time point when the instrument starts working, otherwise the above-mentioned cached recorded time point is cleared and other cached recorded time points are judged.

[0062] Step 3) instrument end working time point judgment

[0063] After the instrument starts working, i.e. after entering the test state, when the working current of the instrument is less than I3, the last current value is subtracted from the current value, and if the change is significant and the difference is greater than D, the current time point is recorded as a to-be-effective state, and whether it is effective is judged;

[0064] The working current of a time period T is read, and when the instrument working current is less than I4 all the time within the time period T, it is determined that this time point is effective and is stored as the time point when the instrument ends working, otherwise the cached recorded time point is cleared and other cached recorded time points are judged.

[0065] Taking the running of the test analysis method A (analysis method of phthalates in toy materials) of the combined instrument as an example, the feasibility of the above-mentioned method is verified.

[0066] Table 1 below shows the parameter setting situation of the test analysis method A in the instrument control software.

[0067] Table 1 Test analysis method A parameter table

[0068]

[0069]

[0070] Figure 4Table 2 shows the current data for GCMS when running method A above. The blue curve represents GC, and the red curve represents MS. Figure 4 The table shows the data corresponding to the GC and MS current curves. The data acquisition frequency for this experiment was once every 30 seconds. The table only shows a portion of the data to ensure accurate correspondence. Figure 4 The horizontal axis is displayed in the image.

[0071] like Figure 4 As shown in Table 2, the current data acquisition frequency F is 30s / time (the time coordinate is compressed due to the influence of the graphic display). When the GC is in standby mode, its operating current fluctuates steadily between 0.5A and 1.5A. When the device is ready, its operating current fluctuates steadily between 1.95A and 2.3A. When the GC starts working, its current value rises rapidly and fluctuates periodically. Let T be the time period required for each test analysis. From the instrument software, T = 10min (GC test cycle). Therefore, only two current thresholds need to be set, denoted as the test start current threshold I1 and the start judgment current I2. In method A, I1 is set to 2.5A and I2 to 5A. When the acquired operating current (set...) When the current exceeds the test start current threshold I1, the current time point is cached and set to a pending state. The operating current for one time period T is read. If the GC operating current exceeds the start judgment current I2 more than three times within the time period, and the interval between the first and last exceedance times is greater than nT, in method A, the parameter n is set to 0.5. That is, if the GC operating current exceeds the start judgment current I2 more than three times within the time period, and the interval between the first and last exceedance times is greater than 0.5T, the current time point is considered valid and stored as the GC device start working time point. Otherwise, the cached time point is cleared, and other cached time points are evaluated. Thus, the GC start working time point can be determined.

[0072] Once the test state is entered, the program for determining the end of the work will be executed. When the GC operating current is less than the end determination current I3, the value in method A is 0.7A. The difference between the previous current value and the current current value is taken, and the difference determination value is set to D, which is set to 3 in method A. When the difference is greater than the set difference determination value D, the current time point is cached and recorded, and this time point is set to pending effect, entering the validity determination stage. Then, the operating current for a time period T is read. If the GC operating current is consistently less than the end threshold current I4 within the time period T, which is set to 2.5A in method A, this time point is determined to be valid and stored as the GC device's end time point. Otherwise, the cached time point is cleared, and other cached time points are determined. Thus, the GC end time point can be determined.

[0073] The determination principle of the MS device is also the same as that of the GC device.

[0074] In combination with the working mode of GCMS, it can be seen that the MS device starts to work after the GC device. The 2.9 min in the mass spectrometer acquisition time in the parameter table of method A represents that the MS device starts to work at the 2.9 min in the period T when the MS device runs once the test analysis method, and ends to work at 10 min, that is, the GC and the MS end to work at the same time in method A (the test time period T of method A is 10 min). From the GCMS current curve spectrum of Figure 4 From the GCMS current curve spectrum of

[0075] Table 2 GCMS time-current data relationship table

[0076]

[0077]

[0078]

[0079] In this case, the working time recorded by the instrument software log information is compared with the working time determined by the method of the embodiment, so as to verify the accuracy of the determination method of the embodiment.

[0080] The instrument software log information shows that the instrument performs test method loading at 10:27 on June 7, 2024, performs instrument tuning and state confirmation at 10:47:27 on June 7, 2024, ends at 10:50:27 on June 7, 2024, and starts to run the test method at 10:58:28 on June 7, 2024, and runs a total of 12 times, and completes the running at 13:55:10 on June 7, 2024.

[0081] By checking the current data collected by the device of the embodiment and the related spectrum, that is, table 2 and Figure 4 It can be seen that the trend change of the current is consistent with the action state in the instrument log.

[0082] The working time period determined by analyzing and processing the collected current data by the method of the embodiment is compared with the working time point recorded in the instrument log, as shown in table 3.

[0083] Table 3 instrument log-the comparison table of the start and end time of the device determined by the method of the embodiment

[0084]

[0085] From the above table, it can be seen that by using the current data of GC or MS, the starting and ending time points of the GCMS test state can be accurately identified by the method of the present embodiment (using MS data, please add the delay test time of 2.9 min in Table 1). In addition, compared with the machine learning method, the method of the present embodiment can save a lot of training time.

[0086] In order to continue to verify whether the state change of the instrument running method can be accurately reflected by current collection, the applicant further adopts the following test scheme:

[0087] The gas chromatography mass spectrometer (GCMS) is used to continuously perform 5 times of determination of method B, and then continuously perform 5 times of determination of method C. In this process, the relevant current data is continuously captured and recorded.

[0088] The experimental results show that the obtained current information not only clearly depicts the state change trend of GCMS during running, but also accurately shows the periodic change characteristics. This result powerfully proves the effectiveness and reliability of monitoring the instrument running state and change by current collection.

[0089] Figure 5 For the current data of GCMS when running the test analysis method B, the blue curve is GC and the red curve is MS. Table 4 is the parameter table of the test analysis method B.

[0090] Table 4 Parameter table of test analysis method B (period T of GC = 27 min)

[0091]

[0092]

[0093] Figure 6 For the current data of GCMS when running the test analysis method C, the blue curve is GC and the red curve is MS. Table 5 is the parameter table of the test analysis method C.

[0094] Table 5 Parameter table of method C (period T of GC = 36 min)

[0095]

[0096]

[0097] The equipment utilization rate refers to the proportion of the time occupied by the equipment in the time provided for creating value. In the TIC industry chemical detection field, because each test needs to determine the test method to be selected according to the test demand of the sample, different test methods have different test periods, the theoretical processing period cannot be fixed, and the TIC industry is different from the manufacturing industry, and there is no concept of unqualified product quantity, that is, the performance utilization rate and the good product rate cannot be calculated. Therefore, the equipment utilization rate represented in the application only refers to the time utilization rate, and the formula is:

[0098]

[0099] For the gas chromatograph mass spectrometer, the running states include four states of shutdown state, standby state, equipment ready state and test state. Among them, the actual working time = the time when the equipment is in the test state, the average downtime maintenance is 1 hour per day, that is, the planned working time per day is 23 hours (note: the equipment is not shut down and maintained every day, and the downtime maintenance time is obtained according to the total maintenance time of each month), and the time utilization rate of the combined instrument can be calculated according to the above formula.

[0100] It needs to be declared for the above log information reading behavior that most brands do not open the communication protocol and encrypt the historical data stored on the instrument software, so another way needs to be found to determine the start and end time of the equipment working state.

[0101] The GCMS device is too flexible, and thousands of test analysis methods can be configured, and the current curve characteristics are different when different test analysis methods are selected, and the current curve characteristics of devices of different manufacturers are also different. If the power characteristic model or the current characteristic model is adopted, the power or current characteristic model needs to be established for each manufacturer and each different model of machine, which is time-consuming and laborious, and cannot be quickly reused and expanded to other manufacturers or other models of GCMS devices. The method of the application, for the GCMS device, only needs to collect a round of current data of the GCMS device for a short time to analyze the current curve characteristics, and seven parameters conforming to the characteristics of the device and the test analysis method are obtained, that is, the current collection frequency F, the test analysis method time period T, the test start current threshold I1, the start determination current threshold I2, the duration coefficient n, the difference determination value D, the test end determination current I3 and the end current threshold I4. Each device can call the algorithm with specific parameters to determine the test start and end time, which not only ensures the accuracy of determining the working state of the device, but also can be quickly reused, greatly reducing the time cost.

Claims

1. A method for statistically analyzing the time uptime of a gas chromatography-mass spectrometry (GC-MS) instrument, wherein the GC-MS instrument comprises a gas chromatograph and a mass spectrometer, characterized in that, The method adopts any of the following schemes: Option 1: Collect the operating current of the gas chromatograph to obtain its current spectrum, identify the start and end times of its test state through an algorithm, and determine the actual working time of the coupled instrument based on this, and calculate the time utilization rate, unless the gas chromatograph ends the test state before the mass spectrometer. In this case, the actual working time of the coupled instrument is corrected according to the test analysis time period T of the gas chromatograph and the mass spectrometry acquisition time recorded in the controlled software of the coupled instrument before calculating the time utilization rate; the mass spectrometry acquisition time refers to the actual working time of the mass spectrometer relative to T. Option 2: Collect the working current of the mass spectrometer to obtain its current spectrum, identify the start and end times of its test state through an algorithm, and determine the actual working time of the coupled instrument based on this. Then, correct the actual working time of the coupled instrument based on the test and analysis time cycle T of the gas chromatograph and the mass spectrometry acquisition time recorded in the control software of the coupled instrument, and calculate the time utilization rate accordingly. The mass spectrometry acquisition time refers to the actual working time of the mass spectrometer relative to T. Option 3: Collect the operating current of the gas chromatograph and mass spectrometer to obtain their current spectra, identify the start and end times of their respective test states through an algorithm, and jointly determine the actual working time of the combined instrument and calculate its time utilization rate. The start and end times of the gas chromatograph and mass spectrometer test status are identified using the following algorithm: Step 1) Define the test start current threshold I1, start judgment current threshold I2, duration coefficient n, difference judgment value D, test end judgment current I3, and end current threshold I4 based on the current trend change characteristics of the configured test analysis method, and obtain the current acquisition frequency F and the test analysis time period T of the gas chromatograph set in the instrument control software; here, I3 <I4≦I1<I2; Step 2) Determining the instrument's start time When the instrument's operating current exceeds I1, the current time point is recorded in the cache and regarded as a pending state, and then the validity is determined. Read the operating current for a time period T. If the instrument's operating current exceeds I2 more than three times within the period and the interval between the first and last times is greater than nT, the recorded time point is determined to be valid and stored as the time point when the instrument starts working. Otherwise, the recorded time point is cleared. Step 3) Determining the instrument's end-of-work time After the instrument enters the test state, when the instrument's operating current is less than I3, the previous current value is taken and the current current value is subtracted. If the change is significant and the difference is greater than D, the current time point is cached and recorded, and it is regarded as a pending state, and then the determination of whether it is effective is entered. Read the operating current for a time period T. If the instrument's operating current is consistently less than I4 within the time period T, then this time point is considered valid and stored as the time point when the instrument ends its operation. Otherwise, clear the cached record of this time point.

2. The method according to claim 1, characterized in that, The data acquisition module uses the following structure to acquire the operating current. The data acquisition module includes a power strip, whose power output port is connected in parallel with its power input port via wires. The data acquisition module also includes a data acquisition unit and several current transformers. The current transformers are connected to each parallel branch to acquire the current on each parallel branch and output it to the data acquisition unit.

3. The method according to claim 2, characterized in that, The structure of the communication system it is based on is as follows: Using the Modbus RTU communication protocol, the server sends acquisition commands to the data acquisition device at the terminal location through the LoRa communication gateway and wireless LoRa communication module, controlling the acquisition device to collect the operating current data of the gas chromatograph and mass spectrometer respectively. The server analyzes and processes the spectrum of the collected current data and calculates the actual working time and time utilization rate of the combined instrument.

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