Eluent level sensor

Abstract

The systems and methods taught herein provide an eluent level sensor that enables real-time monitoring of the level of eluent or waste liquid in a container placed on the eluent level sensor. The eluent level sensor alerts the user if the liquid level of the eluent falls below or exceeds a selectable threshold appropriate for the specific contents of the container. For example, the eluent level sensor can alert the user if the liquid level of the eluent falls below a selectable threshold in a container holding new eluent or eluent precursor. In an eluent delivery system, this helps the user save significant analysis time and effort by alerting them before the container is empty. The eluent level sensor can improve the user experience and avoid damage to instrumentation by notifying the user of the eluent level (e.g., visually).

Description

Technical Field

[0001] The present invention relates to an eluent level sensor.

Background Art

[0002] In liquid measurement systems and various chromatography applications, an end user supplies an eluent that flows through a column. In addition, some effluent fluids are collected as waste. The eluent container is replenished or replaced by the end user when the eluent is used, and the waste container is emptied or replaced with an empty container when the container is filled.

Summary of the Invention

[0003] The technical field of the present disclosure is instruments and applications for analysis. This apparatus can be used in all liquid chromatography applications that require a supply of liquid and the collection of the liquid being analyzed or waste effluent.

[0004]

[0005] The present specification provides an eluent level sensor. The eluent level sensor includes one or more sensors that measure the weight of a container disposed on the eluent level sensor. The eluent level sensor includes a microcontroller that receives and processes signals from the one or more sensors. The microcontroller is configured to set a warning state when a signal from the one or more sensors indicates that the amount of liquid in the container has exceeded a threshold. [Brief explanation of the drawing]

[0006] To facilitate the identification of any particular element or action, the most significant digit in the reference number refers to the figure number in which that element was first introduced. [Figure 1A] Perspective views of eluent level sensors according to various embodiments taught herein are shown. [Figure 1B] Figure 1A shows an exploded view of the eluent level sensor. [Figure 2A] The following are sensor trays according to some embodiments taught herein. [Figure 2B] The following are top views of alternative sensor tray designs according to some embodiments taught herein. [Figure 2C] Figure 2B shows a bottom view of the sensor tray according to some embodiments taught herein. [Figure 3] An exemplary sensor tray according to one embodiment of this disclosure is shown. [Figure 4A] A top perspective view of the upper cover according to one embodiment is shown. [Figure 4B] A bottom perspective view of the upper cover according to one embodiment is shown. [Figure 4C] A cross-sectional view of the upper cover according to some embodiments taught herein is shown. [Figure 5] A partial cross-sectional view of a portion of an eluent level sensor, as taught in various embodiments of this specification, is shown. [Figure 6A] This specification shows optical caps according to several embodiments described herein. [Figure 6B] An exemplary optical cap according to some embodiments described herein is shown. [Figure 7] The underside of an exemplary bottom plate according to several embodiments is shown. [Figure 8] The image shows the underside of a partially constructed eluent level sensor, including the top cover and bottom plate. [Figure 9]An exemplary cover plate according to some embodiments taught herein is shown. [Figure 10] The lower surface of an assembled eluent level sensor according to some embodiments taught herein is shown. [Figure 11] The assembled eluent level sensor, including the optical cap, is shown. [Figure 12] An exemplary electrical connection diagram for an eluent level sensor according to some embodiments taught herein is shown. [Figure 13] A schematic diagram of the electrical connections between the four sensors in some embodiments taught herein is shown. [Figure 14] This specification describes a networked sensing environment, including multiple eluent level sensors connected to an external computing device in the form of an analytical system, according to some embodiments taught herein. [Figure 15A] An embodiment of an eluent level sensor, as taught herein, that holds a container is shown. [Figure 15B] This shows two eluent level sensors stored in an instrument tray for a chromatography apparatus. [Figure 16] This flowchart shows a method for automatically measuring the liquid level in a container for use in a chromatography system. [Modes for carrying out the invention]

[0007] The systems and methods taught herein provide an eluent level sensor that enables real-time monitoring of the eluent level in a container placed on the eluent level sensor. The eluent level sensor alerts the user if the eluent liquid level falls below or exceeds a selectable threshold appropriate for the specific contents of the container. For example, the eluent level sensor can alert the user if the eluent liquid level falls below a selectable threshold in a container holding new eluent or eluent precursor. In eluent delivery systems, this helps users save significant analytical time and effort by alerting them before the container runs out. Furthermore, running out of eluent during system operation can cause irreversible damage to expensive columns in any chromatography system or result in the loss of valuable samples or data. The eluent level sensor can avoid damage to instrumentation and improve the user experience by notifying the user of the current eluent level (e.g., visually). By communicating the availability status of the liquid via the eluent level sensor, the analytical pump of the associated chromatography instrument can be stopped, preventing the pump from drying out due to dry running, thereby extending the lifespan of the pump and its seals.

[0008] In other embodiments, the eluent level sensor can alert the user if the eluent liquid level exceeds a selectable threshold in the container holding the waste discharge. The waste liquid can be collected in the container during the operation of the chromatography system. If attention is not paid to the eluent liquid level in the waste container, the container may become full / overflow, which may cause delays in machine operation during subsequent cleaning or when additional waste cannot be added to the container. The eluent level sensors taught herein can notify the user of the waste eluent liquid level so that the waste can be removed in a timely manner. In some cases, the eluent level sensors taught herein can provide the user with an early indication of excessive eluent waste that may occur when there is a leak in the piping throughout the system. For example, the eluent level sensor corresponding to the container and the eluent level sensor corresponding to the waste container can communicate with each other directly or via an external computing device. A difference between a decrease in the measured fluid level in the eluent container (e.g., a decrease in weight) and an increase in the measured fluid level in the waste container may indicate that a leak has occurred. Alternatively or additionally, an external computing device may identify one or more leakage conditions, such as the presence or absence of leakage, or the degree or severity of leakage, by comparing the measured rate of change (e.g., by weight or volume) of the liquid levels in the eluent container and the waste container with each other or with a desired flow rate (e.g., by measuring the difference).

[0009] The eluent level sensor taught herein can be used to monitor the liquid in a supply bottle or drain bottle (i.e., a bottle from which analyzed fluid is collected) and warn the user if the waste liquid level exceeds a maximum specified threshold, such as the maximum capacity. As will be described in more detail below, the user can set thresholds and other parameters in a graphical user interface of an external computer connected to the eluent level sensor using an interface or protocol (e.g., USB). The eluent level sensor can provide the user with direct visual feedback of light or color to warn the user about the fluid level status of the bottle. In some embodiments, the eluent level sensor can use its own communication protocol with a target host (e.g., an external computer) to provide control and report liquid level data.

[0010] Figures 1A and 1B illustrate perspective and exploded views, respectively, of the eluent level sensor 100 according to some embodiments taught herein. The eluent level sensor 100 includes an upper cover 102, a sensor tray 112, an internal block 114, a bottom plate 116, and a cover plate 120. The sensor tray 112 may include a sensor 122 and a circuit board 124. When a container is placed on the upper cover 102, the eluent level sensor 100 can measure the level of liquid in the container using the total weight of the measured liquid and the container, and stored knowledge about the type of liquid. If the measured level of the eluent falls below a predetermined threshold (in the case of new eluent) or above a preset threshold (in the case of waste liquid), the eluent level sensor 100 can notify the user through a visual indicator on the eluent level sensor 100 itself, through communication from the circuit board 124 to an external computing system, or both. As used herein, the “level” of a fluid may refer to the height of the upper surface of the fluid volume above a baseline, or it may refer to other common expressions of fluid volume, such as total volume, exposed surface area, fluid weight, or fluid mass.

[0011] In some embodiments, the eluent level sensor 100 can widely accept containers having various sizes and shapes of the measurement target, and is not limited to accepting containers of a specific size or shape. For example, the eluent level sensor 100 can accept any form of container including glass bottles, plastic bottles, or other suitable containers. In some embodiments, the eluent level sensor 100 can accept an eluent bottle holding a fluid within the range of 100 mL to 100,000 mL. The eluent level sensor can advantageously accurately measure the volume of any liquid within any container disposed above the eluent level sensor.

[0012] The eluent level sensor can intelligently measure the weight of the entire container containing the liquid and communicate the liquid level to an analysis system (described in more detail below). In some embodiments, the eluent level sensor operates based on the load cell principle, and a plurality of load cells are connected in an electronic bridge manner to measure the total weight. When the liquid level falls below or exceeds a threshold (depending on a specific application), the eluent level sensor can set a warning state and communicate the warning state to the analysis system. The eluent level sensor can warn the user of changes in the liquid level by providing a color of a lit state from green to red (through a visual indicator described below) to any translucent bottle to prompt the user's attention. The external computing device conveys warning information to the user and / or other systems to take corresponding measures. When the eluent is replenished in the delivery system or emptied in the waste system, the eluent level sensor can set a "ready" state (i.e.,解除 the "warning" state) and set the visual indicator to the ready state (e.g., change from red to green).

[0013] In some embodiments, the eluent level sensor 100 is portable and can be moved or positioned on any surface on or around the associated chromatography equipment where eluent is being supplied or waste is being discharged. In some conventional chromatography equipment, the liquid container holder is positioned on top of a cabinet or rack that houses the chromatography equipment. This location can be difficult for shorter users to access and can make it difficult to lift the heavy, liquid-filled container onto the cabinet. The eluent level sensor 100 according to some embodiments of the present disclosure can advantageously be positioned at a different location away from (i.e., not in contact with) the chromatography equipment and / or can be moved to facilitate access after initial placement.

[0014] FIG. 2A shows a sensor tray 112 according to some embodiments described herein. The sensor tray 112 includes one or more cover attachment portions 204, one or more sensor attachment portions 202, an electrical pass-through 206, one or more circuit board attachment portions 208, and a raised portion 210. The cover attachment portion 204 enables proper orientation and positioning of the upper cover 102 when attaching the upper cover 102 to the sensor tray 112. For example, the cover attachment portion 204 can include a latch or friction fit component such as an opening that mates with a compatible object such as a peg on the upper cover 102. In other embodiments, the cover attachment portion 204 includes an opening for receiving the threaded portion of a peg, whereby a nut or other securing mechanism can be attached to the threaded portion on the backside of the sensor tray 112. The sensor attachment portion 202 holds the sensor 122 in a predetermined position under the cover and enables measurement of the amount (e.g., weight) of an object placed on the upper cover. In some embodiments, the sensor attachment portion 202 holds the sensor 122 at an appropriate height above the sensor tray 112 and in contact with the lower surface of the upper cover 102. The sensor 122 thereby receives the weight of the object through contact with the upper cover 102.

[0015] The circuit board mounting section 208 allows the circuit board 124 to be securely connected to the sensor tray 112. For example, the circuit board mounting section 208 may include holes or openings for receiving screws, bolts, or other fasteners placed on or through the circuit board 124. The electrical pass-through 206 provides a path for power cables, communication cables, or both to connect the circuit board 124 to an external power source or external computing device. A strain relief 212 may be provided adjacent to the electrical pass-through 206 through which the electrical cables pass. The strain relief 212 may help prevent damage to the eluent level sensor 100 in the event of a sudden force applied to the electrical cable (for example, if a user trips over the electrical cable or the device falls from a shelf). The strain relief 212 may hold the electrical cable in place and prevent the force applied to the pulled cable from being transmitted to the circuit board 124.

[0016] In various embodiments, the sensor tray 112 may comprise a single piece of molded material or multiple pieces of material attached to one another. The sensor tray 112 may comprise a raised portion 210 that contacts complementary surfaces on the upper cover. In some embodiments, the raised portion 210 may form a seal with respect to the upper cover, preventing fluid from entering the interior of the eluent level sensor. In some embodiments, the sensor tray 112 may be formed by a molding or extrusion process. The sensor tray 112 may comprise an amorphous or semi-crystalline polymer material, such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and these or other polymer materials blended with polycarbonate (PC). In some embodiments, the material may comprise a resin traded under the name Valox®.

[0017] Figure 2B shows a top view of an alternative design of the sensor tray 112 according to some embodiments taught herein. The sensor tray 112 may include a sensor mounting section 202, a circuit board mounting section 208, an electrical pass-through 206, and mounting holes 214. The mounting holes 214 allow the sensor tray 112 to be removably secured to a bottom plate 116 in some embodiments. In this sensor tray 112, the sensor mounting section 202 is located near the corners of the sensor tray 112, whereas in the sensor tray 112 of Figure 2A, the sensor mounting section 202 is located approximately equidistant from the corners of the sensor tray 112.

[0018] Figure 2C shows a bottom view of the sensor tray of Figure 2B according to some embodiments taught herein. The electrical pass-through 206 is shown as a small housing embedded in the sensor tray 112 for routing or consolidating electrical cables coming out of the sensor tray 112.

[0019] Figure 3 shows one embodiment of the sensor tray 112 according to the present disclosure. The illustrated sensor tray 112 includes four sensors 122, a circuit board 124, and an electrical pass-through 206 that enables the circuit board to be connected to an external power supply and an external computing device or an external communication device.

[0020] Sensor 122 may include any suitable sensor that provides a measurable output depending on the application of weight, strain, or stress. Examples of suitable sensors include resistance gauges, capacitive strain gauges, and strain gauge load cells. In some embodiments, sensor 122 is connected directly or indirectly to a microcontroller, as will be described in more detail below. Circuit board 124 may be a printed circuit board in some embodiments.

[0021] In some embodiments, the circuit board 124 may include a visual indicator 302. The visual indicator 302 can provide a visible signal (such as the presence or absence of light or the color of light) to the user to indicate the state of sensing the amount of liquid in a container placed on the eluent level sensor. For example, the visual indicator 302 may light up (i.e., emit light) when the liquid level in the container is such that the user should take further action to empty, refill, or replace the container, and remain off when the state is acceptable. In other embodiments, the visual indicator 302 may emit red light when the liquid level in the container is such that the user should take further action to empty, refill, or replace the container, while emitting green light when the state is acceptable and the user does not need to take further action. It will be understood that in various embodiments, the visual indicator 302 may include a single light-emitting element or other signaling device, or multiple light-emitting elements or signaling devices. In some embodiments, the visual indicator 302 may include one or more light-emitting diodes (LEDs).

[0022] Figure 4A shows a top perspective view of the top cover 102. The top cover 102 includes one or more corner guides 108 to facilitate the positioning of a container onto the top cover 102. In some embodiments, the corner guides 108 are at least partially hollow to be shell-shaped. By providing hollow corner guides 108, the top cover 102 can be manufactured using design-feedback (DFM) principles. In other embodiments, the corner guides 108 can be solid pieces (i.e., not hollow). In various embodiments, the top surface 126 of the top cover 102 may have an area ranging from 10 to 30 square inches. The corner guides of the top cover help the user correctly center the container on the top surface 126. The corner guides assist in gripping and holding the container in an upright position and make it easily visible to the user when positioning a bottle or container on the top cover.

[0023] In some embodiments, the upper cover 102 may be formed by a molding or extrusion process. The upper cover 102 may include amorphous or semi-crystalline polymer materials such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and these or other polymer materials blended with polycarbonate (PC). In some embodiments, the material may include a resin traded under the name Valox®.

[0024] Figure 4B shows a bottom perspective view of the upper cover 102. In this figure, a partially hollow corner guide 108 and a peg 402 can be seen. The peg 402 may include a female or male threaded portion that can be coupled to a complementary bolt or nut, thereby enabling the upper cover 102 to be removably fastened to the sensor tray 112. In some embodiments, the peg 402 is overmolded to increase friction between the peg and the cover mounting portion 204 of the sensor tray 112, thereby ensuring that the upper cover 102 is more securely held by the sensor tray 112. In some embodiments, the thickness of the overmolding on the peg 402 can be selected based on the expected size or weight of the container. For example, the thickness of the overmolding can be selected to be twice as thick for an eluent level sensor fitted to a 4-liter bottle than for an eluent level sensor fitted to a 2-liter bottle.

[0025] Figure 4C shows a cross-sectional view of the upper cover 102. In some embodiments, the height 404 of the corner guide 108 (e.g., measured from the base level to the tip of the corner guide) can be selected based on the type of container to which the eluent level sensor is adapted to measure. In some embodiments, the height 404 can be in the range of 1 inch to 5 inches, or in the range of 2 inches to 3 inches.

[0026] Figure 5 shows a partial cross-sectional view of a portion of the eluent level sensor as taught in various embodiments of this specification. In this figure, the cross-section is taken along a line connecting two circuit board mounting portions 208, as shown, for example, in Figure 2A. Thus, in this figure, the sensor 122 is in the "background". The bottom surface 406 of the upper cover 102 is in direct contact with the sensor 122.

[0027] The optical cap 104 may be formed of a material that is optically transparent all or partially. For example, in some embodiments, the optical cap 104 may be formed of transparent plastic. The optical cap 104 may be permanently or removablely attached to the opening 110 of the upper cover 102. In some embodiments, the optical cap 104 is aligned with the visual indicator 302 so that light emitted from the visual indicator 302 passes through the optical cap 104 and is visible to a user outside the eluent level sensor 100. For example, if the container is transparent, the light can indicate a warning state (e.g., "ready" or "warning / not ready") by visual feedback of intensity or color transmitted through the container. In other words, the visual indicator 302 can illuminate the entire container so that the user can see at a glance from a distance whether the eluent level sensor is ready or whether the container requires maintenance (e.g., waste removal or supply of additional eluent). In some embodiments, the optical cap 104 includes a raised portion or ledge for holding a sealing portion 106 that provides a seal between the optical cap 104 and the opening 110. The sealing portion can prevent a fluid, such as an eluent, from passing through the opening 110 and damaging internal components of the eluent level sensor, such as a circuit board 124. In other embodiments, the sealing portion 106 may be located in a recess within the upper surface 126 of the upper cover 102. In some embodiments, the sealing portion 106 may include a physical barrier, such as a rubber O-ring (or an O-ring made of a different polymer material), an adhesive, such as silicone glue, or a combination of a physical barrier and an adhesive. In some embodiments, the sealing portion 106 can be omitted because the frictional fit between the optical cap 104 and the opening 110 is sufficient to prevent water ingress. The optical cap 104 and the corresponding opening 110 in the upper cover 102 may have any preferred shape, including circular, oval, rectangular (with or without rounded corners), or other shapes, when viewed from directly above.

[0028] The circuit board 124 can be connected to the circuit board mounting portion 208 of the sensor tray 112 using fasteners 502. For example, the fasteners 502 may include screws, adhesives, or other suitable means.

[0029] Figure 6A shows an optical cap 104 according to several embodiments described herein. The optical cap may include one or more engaging mechanisms 602 that engage with the opening 110 of the upper cover 102 to secure the optical cap 104 to the upper cover 102. For example, the engaging mechanism 602 may include one or more clips or hooks having elastic properties, so that the clips or hooks are compressed and pass through the opening 110 and then spring back to their original shape, preventing the optical cap from coming off the opening 110. In some embodiments, the engaging mechanism 602 is disengaged, for example, by applying force to the engaging mechanism 602 and bending it laterally, thereby allowing the optical cap 104 to be removed.

[0030] Figure 6B shows an exemplary optical cap 104 according to some embodiments described herein. The optical cap 104 is made of an optically transparent material.

[0031] Figure 7 shows the underside of an exemplary bottom plate 116 according to several embodiments. The bottom plate 116 may include a recess 118 (depicted as a projection in Figure 7 as it is a photograph showing the underside of the bottom plate 116) and a through hole 702. In some embodiments, the thickness (or height) of the bottom plate 116 can range from 5 mm to 30 mm. The through hole 702 allows the bottom plate to be attached to the sensor tray 112 and / or cover plate 120. The bottom plate 116 may include amorphous or semi-crystalline polymer materials such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and these or other polymer materials blended with polycarbonate (PC). In some embodiments, the material may include a resin traded under the name Valox®.

[0032] The recess 118 is sized and shaped to accommodate the internal block 114. In some embodiments, the internal block 114 may be made of metal. The thickness of the internal block 114 may be in the range of 5 mm to 20 mm, or it may be about 10 mm. The internal block 114 can add weight to the eluent level sensor 100, prevent it from tipping over, and improve the stability of the eluent level sensor 100.

[0033] Figure 8 shows the underside of a partially constructed eluent level sensor 100, including the top cover and bottom plate 116. The electrical cable 802 is shown emerging from a notch in the corner of the bottom plate 116. The electrical cable 802 is wrapped around the outer circumference of a recess 118 (also shown from the underside and appearing as a projection), so that the excess length of the electrical cable 802 can be accommodated and strain relief is provided to avoid the transmission of force from the electrical cable to internal components such as the circuit board 124.

[0034] Figure 9 shows an exemplary cover plate 120 according to some embodiments taught herein. The cover plate 120 includes a recess 902 into which a projection recess 118 of the bottom plate 116 fits. In various embodiments, the cover plate 120 may be formed of a material having a high coefficient of friction, and / or an electrically insulating material, and / or a waterproof or water-repellent material. In some embodiments, the cover plate may be formed of rubber or silicone. In some embodiments, the cover plate 120 is formed by a molding or extrusion process.

[0035] Figure 10 shows the underside of an assembled eluent level sensor 100 according to some embodiments taught herein. The cover plate 120 can cover and hold within the eluent level sensor 100 any excess electrical cables 802 so that the excess cables do not interfere with the stability of the eluent level sensor 100.

[0036] Figure 11 shows the assembled eluent level sensor 100, including the optical cap 104.

[0037] Figure 12 shows an exemplary electrical connection diagram of an eluent level sensor 100 according to some embodiments taught herein. Sensor 122 is connected to a circuit board 124 and transmits a signal proportional to the physical load measured by the sensor (e.g., a changing or constant current or voltage, or other signals indicating resistance, capacitance, or impedance). Specifically, sensor 122 can communicate signals to an analog-to-digital converter (ADC) 1206 on the circuit board 124. In some embodiments, the ADC 1206 acquires a voltage level from the load sensor. The ADC 1206 then converts the analog voltage received from sensor 122 into a digital format and transmits the digital signal to a microcontroller 1202. Communication between the ADC 1206 and the microcontroller 1202 may be performed using a serial protocol in some embodiments. The microcontroller 1202 receives the signal from sensor 122 via the ADC 1206 and processes the signal to convert the digital count from the ADC 1206 into the corresponding liquid level.

[0038] The microcontroller 1202 can compare the determined liquid level with a predetermined threshold. If the liquid level should be above the threshold (i.e., for measuring the container at the input to the device), but is actually below the threshold, the microcontroller 1202 can set a "warning" state. Similarly, if the liquid level should be below the threshold (i.e., for measuring waste liquid), but is actually above the threshold, the microcontroller 1202 can set a "warning" state. If the liquid level is within the acceptable range, the microcontroller 1202 can set a "ready" state.

[0039] Upon receiving a system status of "Ready," the microcontroller 1202 can control the visual indicator 302 to indicate that no user action is required (for example, by illuminating a green LED). Upon receiving a system status of "Warning," the microcontroller 1202 can control the visual indicator 302 to indicate that user action is required (for example, by illuminating a red LED).

[0040] The microcontroller 1202 can also transmit communications to an external computer 1208 to inform it whether the eluent level sensor 100 is in a “ready” or “warning” state. In some embodiments, the microcontroller 1202 transmits a signal to a USB bridge 1204. The USB bridge 1204 encodes, packets, or otherwise prepares the signal information from the microcontroller 1202 for transmission to the external computer 1208 via the electrical cable 802 or wirelessly. In some embodiments, the microcontroller 1202 can transmit binary state information (i.e., “ready” vs “warning”). In some embodiments, the microcontroller 1202 can additionally or alternatively transmit raw sensor data or raw digital signals representing the liquid level in the container to the external computer 1208.

[0041] The external computing device 1208 may include a display for graphically displaying the ready or warning status of the eluent level sensor 100 on a screen. In addition, the external computing device 1208 may include a memory for holding commands to take action based on the ready or warning status of the eluent level sensor 100. For example, the external computing device 1208 may interrupt or prevent the operation of the relevant chromatography equipment if the liquid level in the container is insufficient to allow the chromatography equipment to operate properly. Such a shutdown or preventative action can prevent damage to the chromatography equipment that may occur if the pump is forced to operate in a low flow rate or no flow rate state. Similarly, spills can be prevented by stopping the operation of the relevant chromatography equipment when the waste container is nearing full. Thus, alarm warnings not only help the user to replenish / remove the container but also contribute to extending the lifespan of auxiliary components in the flow path, such as pumps and columns.

[0042] In some embodiments, the microcontroller 1202 may have, or be able to communicate with, a volatile or non-volatile memory that stores parameters enabling the conversion of signals from the sensor 122 into measured liquid levels. One or more parameters may be used when calculating the liquid level based on the measured sensor signals. In some embodiments, the microcontroller 1202 may sense the weight of a container containing the eluent based on the signal from the sensor 122. The microcontroller 1202 may compare the sensed weight to a known weight for the container type stored in memory. As the sensed weight approaches the known weight (i.e., as it approaches the liquid level threshold), the microcontroller 1202 may indicate a warning state because the container is nearly empty. In other embodiments, the memory may store specific gravity values ​​associated with different liquids based on a lookup table or user-input values ​​(e.g., values ​​entered by the user in an external calculator). In some embodiments, the memory may store thresholds to which the liquid level is compared. In some embodiments, the memory may store expected weights for different full container types, empty container types, or both. In some embodiments, the memory may store information about the altitude (above sea level) of the location where the eluent level sensor 100 is located in order to improve the accuracy of weight measurement. The information in the memory can be updated by the user and / or an external computing device 1208. In some embodiments, the eluent level sensor may be a "plug-and-play" device that can operate without initial manual configuration. For example, the microcontroller 1202 and / or memory may store pre-set parameters including bottle type, eluent type, and / or threshold level, and the stored parameters can be used for subsequent executions.

[0043] In some embodiments, the microcontroller 1202 or an external computer may use information from the sensors to determine whether future experimental runs can proceed. When a user initiates one or more sets of chromatographic runs, the external computer and / or the microcontroller 1202 may identify whether there is a sufficient volume of fluid supply to complete the entire series of runs and / or whether the waste volume is currently too large to accommodate the additional waste that will be generated by the runs, and may warn the user in advance. For example, the external computer may notify the microcontroller 1202 that the user wishes to perform one or more experimental runs. The microcontroller 1202 may provide an estimate of the remaining volume of the supply eluent or the remaining empty volume in the waste container. In some embodiments, the microcontroller 1202 may also provide an estimated utilization rate (i.e., the rate at which the waste bottle is filled during a run, or the rate at which the supply bottle is emptied during a run), and the external computer may determine this information from signals provided by the microcontroller. The external computing device can then notify the user to take steps to fill / empty the container until sufficient supply fluid or waste volume is available to accommodate the entire series of runs planned by the user. The eluent level sensor can also provide the user with utilization rates upon request. In some embodiments, the user can propose parameters for an experimental run, and the eluent level sensor can predictively provide estimates of the amount of supply fluid and / or waste that will be required by such a proposed experimental run.

[0044] In some embodiments, the circuit board 124 may include a wireless communication circuit that communicates with nearby objects using active or passive electronic protocols. For example, the wireless communication circuit may be a radio frequency (RF) tag reader or other short-range wireless communication reader, or a Bluetooth® or Wi-Fi communication module. The wireless communication circuit can be connected to the microcontroller 1202 and may be used for the automatic identification of containers, including tags or transmitters adapted to communicate with the short-range wireless communication circuit. Information received from the container by the wireless communication circuit may include one or more of the following: container identification information, specifications of the container size or shape, specifications of the type of liquid in the container, or specifications of the density or specific gravity of the fluid in the container. Based on the received information, the microcontroller 1202 can automatically set parameters including the type and size of the bottle, and even an arbitrary assigned fluid type. For example, the microcontroller 1202 can access known container weight values ​​from memory related to the type of container, such as that identified by the information from the communication circuit. This information can then be stored in memory and, in some embodiments, used to convert signals from measured sensors into liquid weight, level, or volume information.

[0045] In some embodiments, an external computing device can continuously ping the microcontroller 1202 with level information and status relative to a set threshold. The physical electrical layer for communication between the eluent level sensor and the external computing device can be a Universal Serial Bus (USB), but the communication protocol may include custom or proprietary commands in some embodiments.

[0046] In some embodiments, the sensor 122 is of a type known as a strain gauge load cell. Strain gauge load cells are found in industrial environments. Strain gauge load cells can be highly accurate, versatile, and cost-effective. Structurally, this type of sensor has a metal body on which the strain gauge is fixed. The body is usually made of aluminum, alloy steel, or stainless steel, which makes it very robust but has minimal elasticity. This elasticity gives rise to the term "spring element," which refers to the body of the load cell. When a force is applied to the load cell, the spring element deforms slightly and returns to its original shape unless it is overloaded. As the spring element deforms, the strain gauge also changes shape. The change in resistance of the strain gauge can be measured as a voltage. Since the change in voltage is proportional to the amount of force applied to the cell, the amount of force can be calculated from the output of the load cell.

[0047] In some embodiments, the change in resistance measured by a single strain gauge sensor can be extremely small, making it difficult to accurately measure the change. These small changes can be magnified to be more measurable by increasing the number of strain gauges applied together. Figure 13 shows a schematic diagram of the electrical connections between four sensors 122 in some embodiments taught herein. The four sensors 122 can be arranged as a Wheatstone bridge. A Wheatstone bridge is a configuration of four balanced resistors to which a known excitation voltage is applied, as shown in Figure 13.

[0048] In some embodiments, the basic principle of operation is to measure the weight of the eluent along with the container using four load cell sensors arranged in a Wheatstone bridge array. These are strain gauges, and their resistance changes when deflection occurs due to strain. This change is resistance and is measured as a change in voltage by an ADC 1206 on circuit board 124. The ADC 1206 is connected to a microcontroller 1202, which takes the output from the ADC 1206 and calculates the level according to user-defined parameters. The microcontroller 1202 can also control a visual indicator 302, such as a green LED, when the liquid level is above a threshold level (in the eluent delivery system) or below a threshold level (in the eluent disposal system). This indicates to the user that the liquid level is significantly above / below a set threshold. Each time the liquid level crosses or exceeds the threshold level, the microcontroller 1202 can control the visual indicator 302 to change the color of the green LED, for example, to red. This allows users to easily identify containers that need refilling (in the eluent delivery system) or containers that need to be emptied (in the eluent disposal system).

[0049] Figure 14 shows a networked sensing environment 1404 including a plurality of eluent level sensors 100 connected to an external computing device 1208 in the form of an analytical system, according to some embodiments taught herein. Although the figure shows eluent level sensors 100 connected via electrical cables 802, the disclosure is not limited to such arrangements, and the eluent level sensors 100 may be connected by other means, such as via wireless connection (e.g., Bluetooth® or Wi-Fi) or via an intermediate network or network protocol (e.g., via a local area network or via the Internet).

[0050] In some embodiments, the number of sensors 122 in a size range connected to a single external computing device 1208 (e.g., an analysis system) can reach 256. Once the user 1406 sets parameters for each sensor module (e.g., container type, fluid type, initial fill level), the analysis system tracks the liquid level in each container associated with the sensor. The user 1406 can access the external computing device 1208 to monitor the status of the entire array of eluent level sensors 100 at a glance. The user 1406 can also use the external computing device to add or modify parameters in the memory of one or more of the eluent level sensors 100. In some embodiments, the user 1406 can use a control program on the external computing device or another connected device that controls the associated chromatography equipment to take measures based on the status of the eluent level sensors, such as pausing operation to allow for liquid replenishment.

[0051] The visual indicators 302 of each eluent level sensor 100 in the networked sensing environment 1404 can provide the system user 1406 with immediate relevant information. In other words, eluent level sensors can help a user monitor multiple containers located in different locations within their laboratory / workspace. In large laboratories with many chromatography instruments in operation, conventional methods can make it difficult for a user to identify which container in the system is causing a warning condition. For example, a user of a conventional system may have to rely on an ID or barcode identifier provided by a computing device and search the laboratory to compare this information with the identifier on each individual container. By using the visual indicators 302 as taught herein, the user can immediately determine the location of an eluent level sensor 100 in the networked sensing environment 1404 that is indicating a warning.

[0052] In some embodiments, the external computing device 1208 can use sensor data to provide advance warnings to the user and / or related systems about the available liquid volume, or to provide periodic feedback during operation. The eluent level sensor 100 can communicate continuously with the external computing device 1208 to provide information and warnings regarding the liquid volume or level.

[0053] In some embodiments, the microcontroller 1202 or external computing device 1208 can transmit tracking data specific to a particular eluent level sensor or container to a cloud-managed database system for laboratory information management. This communication can help track the location of containers within the laboratory or facility and enable efficient reordering of new containers or eluents if it is determined that a set number of warnings have been triggered, indicating that the liquid level in a particular container is low and / or that a certain amount of eluent stock has been used up.

[0054] Figure 15A illustrates an embodiment of the eluent level sensor 100, as taught herein, which holds a container 1402. In some embodiments, the eluent level sensor 100 may be sized or shaped to hold a container of a specific or predetermined size or shape. For example, the eluent level sensor may be sized to support a 1-liter, 2-liter, 4-liter, or other appropriately sized container, whether cylindrical, rectangular, prismatic, or other shape. In other embodiments, the eluent level sensor may be designed to fit a range of container sizes. For example, corner guides may be extendable in some embodiments to allow stabilization of taller containers. Similarly, the top cover may have extension elements that allow for an increase in the length or width of the installation area of ​​the eluent level sensor.

[0055] Figure 15B shows two eluent level sensors 100 housed in an instrument tray 1502 for chromatography equipment. The instrument tray 1502 can, advantageously, be a removable part of the chromatography equipment, including a handle to facilitate user operation and allow the user to firmly grip the instrument tray 1502. In some embodiments, the instrument tray 1502 is positioned on top of the chromatography equipment cabinet or rack. In other embodiments, the instrument tray 1502 or a single eluent level sensor 100 can be placed away from (i.e., without contact with) the chromatography equipment, such as on the floor or another work surface. In this sense, the systems and methods described herein may differ from some conventional systems where the container can only be placed on top of the chromatography equipment itself and not elsewhere. Whether positioned on top of the equipment, adjacent to the equipment, or remotely, the eluent level sensors taught herein can be modular and can be placed anywhere for general use with analytical instruments such as chromatography equipment. As portable devices, the eluent level sensors can be placed on the equipment or on a laboratory bench. This gives users the flexibility to place multiple containers anywhere in their surroundings.

[0056] Figure 16 shows a flowchart of method 1602 for automatically measuring the liquid level in a container for use in a chromatography system. While this method considers one eluent level sensor 100, those skilled in the art will understand that multiple eluent level sensors 100 may be involved in the system. In block 1604, the container is positioned on the eluent level sensor 100. For example, the container may be positioned on an upper cover 102 and held in place by corner guides 108. This container may be a bottle for supplying eluent to the system for analysis, or a bottle for collecting waste or used eluent. In an optional block 1606, method 1602 may perform an initial measurement to establish a baseline before the removal or addition of eluent begins. A microcontroller and / or external computer can use the baseline to eliminate the influence of the container and tube on subsequent measurements (e.g., by subtracting the baseline value). For example, the user may initialize the eluent level sensor (e.g., tare) based on an empty container before filling the container with eluent (if the container is collecting waste eluent). Alternatively or additionally, initialization may include setting a threshold based on an initial weight measurement. For example, the eluent level sensor may compare the initial measurement to data on a full container stored in memory to determine where the threshold should be set. In optional block 1608, if there is liquid pre-filled in the container before measurement begins, the user can input an approximate existing volume. The liquid level may be received from the user by the microcontroller and / or external computer. This helps the eluent level sensor perform and track accurate measurements. In optional block 1610, the microcontroller or external computer may receive additional parameters from the user, such as information on whether the container is one of a predetermined bottles for which information is stored in memory, or whether the container is a custom bottle.The user can modify parameters accessible to the microcontroller 1202 of the eluent level sensor 100, such as the type of liquid, the total usable volume of the container, a user-specified upper threshold volume, or a user-specified lower threshold volume. If a custom bottle is selected in block 1606 or block 1610, variations in the tubing, fittings, and ferrules can also be taken into account during subsequent measurements. This helps the user obtain more accurate and realistic fluid data from the eluent level sensor.

[0057] In block 1610, the user can also input and record notes such as the name and type of liquid to an external computer (e.g., via a graphical user interface) or microcontroller. Control variables can be stored in memory and may include high / low thresholds and brightness levels of visual indicators. When using custom bottles, the user can also determine the expected maximum volume of the bottle. In block 1612, the eluent level sensor can measure the liquid level in the container using one or more sensors. For example, the eluent level sensor can determine the weight difference between the current measurement, the initial measurement, or a calculated or stored value. The eluent level sensor 100 can continuously communicate the measurement by transmitting information to an external computer. In some examples, the external computer or microcontroller can continuously display the changing state of the eluent in the container. If the amount of liquid (e.g., eluent, precursor, or waste) exceeds a threshold (e.g., depending on whether the container is full or waste, the amount is above or below the threshold), the user is warned (block 1614). For example, an external computing device can deploy visual indicators on a graphical user interface. Similarly, the eluent level sensor itself can activate or modify a visual indicator on the unit's body to warn the user. For example, the eluent level sensor can change the intensity or color of the light emitted through the light cap and through the transparent container (or below the container if the container is too opaque to allow the indicator light to pass through). In addition, relevant measures, such as a forced shutdown of the fluid pump (to prevent damage due to dry running), can be taken immediately or after a delay if the user fails to take action. Blocks 1612 and 1614 can be repeated over time to send further alerts to the user if the eluent level sensor continuously monitors the liquid level in the container and the state changes (i.e., if the light characteristics or indicator state changes after the user has addressed a warning state and the "ready" state has been achieved).

[0058] Although this instruction is described in conjunction with various embodiments, it is not intended to limit this instruction to those embodiments. Rather, this instruction encompasses a variety of substitutes, variations, and equivalents, as will be understood by those skilled in the art.

[0059] Furthermore, in the descriptions of various embodiments, this specification may present methods and / or processes as a specific order. However, unless the method or process relies on a specific order of steps described herein, the method or process should not be limited to that specific order of steps. As those skilled in the art will understand, other orders of steps are possible. Therefore, the specific order of steps described herein should not be interpreted as a limitation in the claims. In addition, it will be readily apparent to those skilled in the art that the claims relating to the method and / or process should not be limited to the implementation of those steps in the order written, and the order may be changed, still remaining within the spirit and scope of various embodiments.

[0060] The embodiments described herein can be carried out using handheld devices, microprocessor systems, other computer system configurations including microprocessor-based or programmable home appliances, minicomputers, mainframe computers, etc. The embodiments can also be carried out by distributing the computing environment in which tasks are performed by remote processing units linked over a network.

[0061] It should be understood that the embodiments described herein can also be used for a variety of computer implementations involving data stored in a computer system. These operations require the physical manipulation of physical quantities. Typically, but not always, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated. Furthermore, the operations performed include, in terms of terminology, generating, identifying, determining, or comparing.

[0062] Any of the operations that form part of the embodiments described herein are useful mechanical operations. Embodiments described herein also refer to devices or apparatus for performing these operations. The systems and methods described herein may be built specifically for a particular purpose, or they may be general-purpose computers selectively operated or configured by computer programs stored in the computer. Specifically, various general-purpose machines may be used with computer programs written in accordance with the teachings herein, or it may be more convenient to build more specialized apparatus to perform a particular operation.

[0063] Certain embodiments can also be embodied as computer-readable code on a computer-readable medium. A computer-readable medium is any data storage device that can store data and is subsequently readable by a computer system. Examples of computer-readable media include hard drives, network-attached storage (NAS), read-only memory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical or non-optical data storage devices. Computer-readable media can also be distributed across a network-connected computer system so that the computer-readable code is stored and executed in a distributed manner.

[0064] The advantages and features of this disclosure can be further illustrated by the following embodiments. Example 1. The eluent level sensor comprises one or more sensors that measure the weight of a container placed on the eluent level sensor, and a microcontroller that receives and processes signals from one or more sensors, and is configured to set a warning state when the signals from one or more sensors indicate that the amount of liquid in the container exceeds a threshold.

[0065] Example 2. The eluent level sensor according to Example 1, wherein the microcontroller is configured to process signals from one or more sensors and compare the measured weight of the container with a known weight of the container stored in memory.

[0066] Example 3. The eluent level sensor according to Example 1 or 2, wherein the microcontroller is configured to process signals from one or more sensors and determine the weight or volume of the liquid in the container using specific gravity values ​​stored in memory.

[0067] Example 4. An eluent level sensor according to any one of Examples 1 to 3, wherein the liquid is waste eluent and the threshold is the maximum volume.

[0068] Example 5. An eluent level sensor according to any one of Examples 1 to 3, wherein the liquid is a new eluent or eluent precursor.

[0069] Example 6. The eluent level sensor according to Example 5, wherein the microcontroller is configured to identify a leakage condition by comparing signals from one or more sensors with signals from sensors corresponding to the waste container.

[0070] Example 7. The eluent level sensor according to any one of Examples 1 to 6, wherein the eluent level sensor is configured to communicate with an external computing device having a graphical user interface configured to allow the user to set a threshold.

[0071] Example 8. An eluent level sensor according to any one of Examples 1 to 7, further comprising a light cap aligned with a visual indicator to indicate a warning state by visual feedback of light or color transmitted through the container.

[0072] Example 9. The eluent level sensor according to Example 7, wherein the optical cap is detachably engaged with the upper cover of the eluent level sensor.

[0073] Example 10. The eluent level sensor is an eluent level sensor according to any one of Examples 1 to 9, which provides a warning state to an external computing device.

[0074] Example 11. An eluent level sensor according to any one of Examples 1 to 10, wherein one or more sensors include a plurality of load cells connected in the manner of a Wheatstone bridge.

[0075] Example 12. The eluent level sensor according to any one of Examples 1 to 11, wherein the microcontroller is configured to set a ready state when the amount of liquid does not exceed, or no longer exceeds, a threshold.

[0076] Example 13. An eluent level sensor according to any one of Examples 1 to 12, wherein the eluent level sensor is portable, can be repositioned after initial placement, or can be placed away from the chromatography equipment.

[0077] Example 14. An eluent level sensor according to any one of Examples 1 to 13, further comprising an upper cover for supporting a container, and a sensor tray including a raised portion configured to seal to the upper cover and prevent fluid from entering the interior of the eluent level sensor.

[0078] Example 15. The eluent level sensor according to Example 14, wherein the top cover is at least partially hollow and includes one or more corner guides to facilitate positioning of the container onto the top cover.

[0079] Example 16. The eluent level sensor according to any one of Examples 1 to 15, further comprising an internal block for improving the stability of the eluent level sensor.

[0080] Example 17. The eluent level sensor according to any one of Examples 1 to 16, wherein the microcontroller is configured to stop the operation of the fluid pump when a warning state is set.

[0081] Example 18. The eluent level sensor according to Example 1, wherein the microcontroller determines the liquid usage rate over time and provides the usage rate to the user.

[0082] Example 19. An eluent level sensor according to any one of Examples 1 to 18, further comprising a wireless communication circuit that communicates with a container tag or transmitter to determine at least one of the following: container identification information, container size, container shape, type of liquid in the container, or density or specific gravity of the liquid in the container.

[0083] Example 20. A method for automatically measuring the liquid level in a container for use in a chromatography system, the method comprising: placing the container on an eluent level sensor, the eluent level sensor comprising one or more sensors for measuring the weight of the container placed on the eluent level sensor, and a microcontroller for receiving and processing signals from one or more sensors; using the microcontroller to measure the amount of liquid in the container based on the signals from one or more sensors; and warning the user if the amount of liquid exceeds a threshold.

[0084] Example 21. The method according to Example 20, wherein measuring the liquid volume includes comparing the measured weight of the container with a known weight of the container stored in memory.

[0085] Example 22. The method according to Example 20 or 21, wherein measuring the liquid volume includes processing signals from one or more sensors and determining the weight or volume of the liquid in the container using specific gravity values ​​stored in memory.

[0086] Example 23. The method according to any one of Examples 20-22, wherein the liquid is a waste eluent and the threshold is the maximum volume.

[0087] Example 24. The method according to any one of Examples 20 to 22, wherein the liquid is a new eluent or eluent precursor.

[0088] Example 25. The method according to Example 24, further comprising identifying a leakage condition by comparing signals from one or more sensors with signals from additional sensors corresponding to a waste container.

[0089] Example 26. The method according to any one of Examples 20 to 25, further comprising receiving a threshold from a user via a graphical user interface of an external computing device.

[0090] Example 27. The method according to any one of Examples 20-26, further comprising changing the visual feedback of the intensity or color of light transmitted through the container using a visual indicator aligned with a light cap in the eluent level sensor to warn the user.

[0091] Example 28. The method according to Example 26, wherein the optical cap is detachably engaged with the upper cover of the eluent level sensor.

[0092] Example 29. The method according to any one of Examples 20 to 28, wherein warning the user includes providing warning information to an external computing device.

[0093] Example 30. The method according to any one of Examples 20 to 29, wherein one or more sensors include a plurality of load cells connected in the manner of a Wheatstone bridge.

[0094] Example 31. The method according to any one of Examples 20 to 30, further comprising setting a ready state when the amount of liquid does not exceed, or no longer exceeds, a threshold.

[0095] Example 32. The method according to any one of Examples 20 to 31, further comprising moving the eluent level sensor, repositioning the eluent level sensor after initial placement, or placing the eluent level sensor away from the chromatography instrument.

[0096] Example 33. The method according to any one of Examples 20 to 32, wherein arranging the eluent container includes placing the container on the upper cover of the eluent level sensor and supporting the container, and the method further includes sealing the raised portion of the sensor tray against the upper cover to prevent fluid from entering the interior of the eluent level sensor.

[0097] Example 34. The method according to Example 33, wherein arranging the eluent container involves holding the container using one or more corner guides that are at least partially hollow in the top cover.

[0098] Example 35. The method according to any one of Examples 20 to 34, wherein the eluent level sensor further comprises an internal block for increasing the stability of the eluent level sensor.

[0099] Example 36. The method according to any one of Examples 20 to 35, further comprising stopping the operation of the fluid pump after warning the user.

[0100] Example 37. The method according to any one of Examples 20 to 36, further comprising determining the liquid usage rate over time and providing the usage rate to the user.

[0101] Example 38. The method according to any one of Examples 20 to 37, further comprising using a wireless communication circuit to communicate with a container tag or transmitter and determining at least one of the following: container identification information, container size, container shape, type of liquid in the container, or density or specific gravity of the liquid in the container.

Claims

1. An eluent level sensor, One or more sensors that measure the weight of a container placed on the eluent level sensor, A microcontroller that receives and processes signals from one or more sensors, and is configured to set a warning state when the signals from one or more sensors indicate that the amount of liquid in the container exceeds a threshold, An eluent level sensor equipped with the following features.

2. The eluent level sensor according to claim 1, wherein the microcontroller is configured to process the signals from one or more sensors and to compare the measured weight of the container with a known weight of the container stored in memory.

3. The eluent level sensor according to claim 1, wherein the microcontroller is configured to process the signals from one or more sensors and to determine the weight or volume of the liquid in the container using the specific gravity values ​​stored in memory.

4. The eluent level sensor according to claim 1, wherein the liquid is a waste eluent and the threshold is the maximum volume.

5. The eluent level sensor according to claim 1, wherein the liquid is a new eluent or eluent precursor.

6. The eluent level sensor according to claim 5, wherein the microcontroller is configured to determine the leakage state by comparing signals from one or more sensors with signals from sensors corresponding to waste containers.

7. The eluent level sensor according to claim 1, wherein the eluent level sensor is configured to communicate with an external computing device having a graphical user interface configured to allow a user to set the threshold.

8. The eluent level sensor according to claim 1, further comprising a light cap aligned with a visual indicator to indicate the warning state by visual feedback of light or color transmitted through the container.

9. The eluent level sensor according to claim 8, wherein the optical cap is detachably engaged with the upper cover of the eluent level sensor.

10. The eluent level sensor according to claim 1, wherein the eluent level sensor provides the warning state to an external computing device.

11. The eluent level sensor according to claim 1, wherein the one or more sensors include a plurality of load cells connected in the manner of a Wheatstone bridge.

12. The eluent level sensor according to claim 1, wherein the microcontroller is configured to set a ready state when the amount of liquid does not exceed the threshold, or no longer exceeds the threshold.

13. The eluent level sensor according to claim 1, wherein the eluent level sensor is portable, can be repositioned after initial placement, or can be placed away from the chromatography equipment.

14. An upper cover that supports the container, A sensor tray including a raised portion configured to seal the upper cover and prevent fluid from entering the interior of the eluent level sensor, The eluent level sensor according to claim 1, further comprising the above.

15. The eluent level sensor according to claim 14, wherein the upper cover is at least partially hollow and includes one or more corner guides to facilitate positioning of the container on the upper cover.

16. The eluent level sensor according to claim 1, further comprising an internal block for improving the stability of the eluent level sensor.

17. The eluent level sensor according to claim 1, wherein the microcontroller is configured to stop the operation of the fluid pump when the warning state is set.

18. The eluent level sensor according to claim 1, wherein the microcontroller determines the usage rate of the liquid over time and provides the usage rate to the user.

19. The eluent level sensor according to claim 1, further comprising a wireless communication circuit that communicates with a tag or transmitter of the container in order to determine at least one of the following: identification information of the container, the size of the container, the shape of the container, the type of liquid in the container, or the density or specific gravity of the liquid in the container.

20. A method for automatically measuring the liquid level in a container for use in a chromatography system, wherein the method is: The arrangement involves placing a container on an eluent level sensor, wherein the eluent level sensor includes one or more sensors that measure the weight of the container placed on the eluent level sensor, and a microcontroller that receives and processes signals from the one or more sensors. Using the microcontroller, the amount of liquid in the container is measured based on the signals from one or more sensors, The system warns the user when the amount of liquid exceeds a threshold, Methods that include...

21. The method according to claim 20, wherein measuring the liquid volume includes comparing the measured weight of the container with a known weight of the container stored in memory.

22. The method according to claim 20, wherein measuring the amount of liquid includes processing the signals from one or more sensors to determine the weight or volume of the liquid in the container using specific gravity values ​​stored in memory.

23. The method according to claim 22, wherein the liquid is a waste eluent and the threshold is the maximum volume.

24. The method according to claim 22, wherein the liquid is a new eluent or eluent precursor.

25. The method according to claim 24, further comprising determining a leakage condition by comparing signals from one or more sensors with signals from additional sensors corresponding to a waste container.

26. The method according to claim 20, further comprising receiving the threshold from a user via a graphical user interface of an external computing device.

27. The method according to claim 20, further comprising warning the user by changing the visual feedback of the intensity or color of light transmitted through the container using a visual indicator aligned with a light cap in the eluent level sensor.

28. The method according to claim 27, wherein the optical cap is detachably engaged with the upper cover of the eluent level sensor.

29. The method according to claim 20, wherein warning the user includes providing warning information to an external computing device.

30. The method according to claim 20, wherein the one or more sensors include a plurality of load cells connected in the manner of a Wheatstone bridge.

31. The method according to claim 22, further comprising setting a ready state if the amount of the liquid does not exceed, or no longer exceeds, the threshold.

32. The method according to claim 20, further comprising moving the eluent level sensor, repositioning the eluent level sensor after initial placement, or placing the eluent level sensor away from the chromatography equipment.

33. Placing the eluent container includes placing the container on the upper cover of the eluent level sensor and supporting the container, and the method is The method according to claim 20, further comprising sealing the raised portion of the sensor tray with respect to the upper cover to prevent fluid from entering the interior of the eluent level sensor.

34. The method according to claim 33, wherein positioning the eluent container involves holding the container using one or more corner guides that are at least partially hollow of the upper cover.

35. The method according to claim 20, wherein the eluent level sensor further comprises an internal block for improving the stability of the eluent level sensor.

36. The method according to claim 20, further comprising stopping the operation of the fluid pump after warning the user.

37. The method according to claim 22, further comprising determining the usage rate of the liquid over time and providing the usage rate to the user.

38. The method according to claim 20, further comprising using a wireless communication circuit to communicate with a tag or transmitter of the container and determining at least one of the following: identification information of the container, the size of the container, the shape of the container, the type of liquid in the container, or the density or specific gravity of the liquid in the container.

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