Special tool for fault diagnosis of thermal conductivity detector of gas chromatograph

Abstract

A gas chromatograph thermal conductivity detector fault diagnosis special tool comprises precision resistors, an insulating plate and a plastic instrument box, the insulating plate is installed in the plastic instrument box, the precision resistors are installed on the insulating plate, the number of the precision resistors is four, the precision resistors are an R3 resistor, an R1 resistor, an R2 resistor and an R4 resistor which are sequentially connected in series, the R3 resistor is not connected with the R4 resistor, and the R1 resistor is connected with the R2 resistor. The first terminal of the thermal conductivity detector TCD is connected between the resistor R1 and the resistor R2, the second terminal of the thermal conductivity detector TCD is connected between the resistor R1 and the resistor R3, the front end of the resistor R3 is connected to the third terminal of the thermal conductivity detector TCD, the rear end of the resistor R4 is connected to the fourth terminal of the thermal conductivity detector TCD, and the fifth terminal of the thermal conductivity detector TCD is connected between the resistor R2 and the resistor R4. The tool is low in cost, fault points can be quickly and accurately judged, and fault misjudgment is avoided. Working efficiency is improved, and use and maintenance cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas chromatographs, and in particular relates to a special tool for diagnosing faults of a thermal conductivity detector of a gas chromatograph. Background Art

[0002] Gas chromatograph is one of the large-scale precision analytical instruments commonly used in laboratory analysis and online analysis. Thermal conductivity detector is the key core precision component of gas chromatograph. Once any fault occurs in thermal conductivity detector, normal analysis will not be possible. Therefore, daily maintenance and fault inspection and judgment of thermal conductivity detector are crucial. The degree of contamination, balance of hot wire, insulation quality, carrier gas purity and flow stability of thermal conductivity detector itself are all related. It is impossible to quickly and accurately judge the fault point according to the fault phenomenon. Since the thermal conductivity detector itself is small in size, the hot wire is thin, and the price is high, the imported one generally costs tens of thousands of yuan, and the delivery time is long, which brings great difficulty to daily maintenance work. During cleaning, disassembly and installation, the hot wire will break or the installed insulation will not meet the requirements if you are not careful, the instrument will not work properly, and a serious short circuit will damage the mainboard, causing unnecessary economic losses. Utility Model Content

[0003] Aiming at the problem of fault inspection and diagnosis of thermal conductivity detector of gas chromatograph and avoiding unnecessary thermal conductivity detector maintenance work due to misdiagnosis of fault point, the utility model provides a special tool for fault diagnosis of thermal conductivity detector of gas chromatograph.

[0004] A special tool for fault diagnosis of thermal conductivity detector of gas chromatograph, characterized in that it includes precision resistors, insulating plates and plastic instrument box, the insulating plates are installed in the plastic instrument box, the precision resistors are installed on the insulating plates, there are four precision resistors, namely R3 resistor, R1 resistor, R2 resistor and R4 resistor connected in series in sequence, and R3 resistor and R4 resistor are not connected, the connection between R1 resistor and R2 resistor is connected to the first terminal of thermal conductivity detector TCD, the connection between R1 resistor and R3 resistor is connected to the second terminal of thermal conductivity detector TCD, the front end of R3 resistor is connected to the third terminal of thermal conductivity detector TCD, the rear end of R4 resistor is connected to the fourth terminal of thermal conductivity detector TCD, and the connection between R2 resistor and R4 resistor is connected to the fifth terminal of thermal conductivity detector TCD.

[0005] Furthermore, the resistance values ​​of the R3 resistor, the R1 resistor, the R2 resistor and the R4 resistor are all 50Ω, the difference is ≤0.5Ω, and the power is all 2W.

[0006] The beneficial effect of the utility model is that after the tool is connected, the whole machine is powered on and started to run. If the fault disappears immediately, it means that there is a problem with the thermal conductivity detector in the original chromatograph host. At this time, the thermal conductivity detector must be specially repaired and inspected, cleaned, reinstalled or replaced. If the chromatograph fault phenomenon still exists after the connection, it is necessary to continue to check other reasons of the chromatograph item by item. The tool is low-cost and can quickly and accurately determine the fault point to avoid misjudgment of the fault. It improves work efficiency and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic diagram of the structure of a special tool for fault diagnosis of thermal conductivity detector of gas chromatograph.

[0008] Among them: 1-plastic instrument box, 2-insulating board, 3-R1 resistor, 4-R2 resistor, 5-R3 resistor, 6-R4 resistor, 7-first terminal, 8-second terminal, 9-third terminal, 10-fourth terminal, 11-fifth terminal. DETAILED DESCRIPTION

[0009] Example 1: A special tool for fault diagnosis of thermal conductivity detector of gas chromatograph includes a precision resistor, an insulating plate 2 and a plastic instrument box 1. The insulating plate 2 is installed in the plastic instrument box 1, and the precision resistor is installed on the insulating plate 2. There are four precision resistors, namely R3 resistor 5, R1 resistor 3, R2 resistor 4 and R4 resistor 6 connected in series in sequence, and R3 resistor 5 and R4 resistor 6 are not connected. The resistance values ​​of R3 resistor 5, R1 resistor 3, R2 resistor 4 and R4 resistor 6 are all 50Ω, the difference is ≤0.5Ω, and the power is all 2w. During the maintenance of gas chromatograph thermal conductivity detector TCD, when the maintenance personnel suspect that the gas chromatograph thermal conductivity detector TCD is faulty after eliminating other circuit and gas line faults, they only need to disconnect the thermal conductivity detector wiring in the original chromatograph host, connect the R1 resistor 3 and R2 resistor 4 in the tool to the first terminal 7 of the thermal conductivity detector TCD, connect the R1 resistor 3 and R3 resistor 5 to the second terminal 8 of the thermal conductivity detector TCD, connect the front end of R3 resistor 5 to the third terminal 9 of the thermal conductivity detector TCD, connect the rear end of R4 resistor 6 to the fourth terminal 10 of the thermal conductivity detector TCD, and connect the R2 resistor 4 and R4 resistor 6 to the fifth terminal 11 of the thermal conductivity detector TCD. After connecting the tool, the whole machine is powered on and started to run. Because the bridge circuit of the tool is statically balanced, that is, the resistance value is constant, it can overcome the influence of external variable factors such as temperature, pollution, current, insulation, carrier gas, etc. on the thermal conductivity detector bridge circuit, and can intuitively and accurately reflect whether it is a thermal conductivity detector failure, thereby accurately judging whether it is a thermal conductivity detector failure of the original chromatograph host. If the fault disappears immediately, it means that there is a problem with the thermal conductivity detector in the original chromatograph host. At this time, the thermal conductivity detector must be specially repaired, cleaned, reinstalled or replaced. If the chromatograph fault phenomenon still exists after the connection, other reasons for the chromatograph must be checked item by item.

Claims

1. A special tool for fault diagnosis of thermal conductivity detector of gas chromatograph, characterized by: It includes a precision resistor, an insulating plate and a plastic instrument box. The insulating plate is installed in the plastic instrument box, and the precision resistor is installed on the insulating plate. There are four precision resistors, which are R3 resistor, R1 resistor, R2 resistor and R4 resistor connected in series in sequence, and the R3 resistor is not connected to the R4 resistor. The R1 resistor and the R2 resistor are connected to the first terminal of the thermal conductivity detector TCD, the R1 resistor and the R3 resistor are connected to the second terminal of the thermal conductivity detector TCD, the front end of the R3 resistor is connected to the third terminal of the thermal conductivity detector TCD, the rear end of the R4 resistor is connected to the fourth terminal of the thermal conductivity detector TCD, and the R2 resistor and the R4 resistor are connected to the fifth terminal of the thermal conductivity detector TCD.

2. The gas chromatograph thermal conductivity detector fault diagnosis tool as claimed in claim 1, characterized in that The resistance values ​​of the resistors R3, R1, R2 and R4 are all 50Ω, the difference is ≤0.5Ω, and the power is all 2W.

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