Due to the complex structure of the gas chromatograph, many working conditions are set, and the recovery preparation time is long, various abnormalities often occur during use. If not treated according to the cause, it will cause serious consequences. Let's discuss today's baseline failure:

First, the benchmark drift.

1. Insufficient gas cylinder pressure: replace the gas cylinder. In order to prevent residual gas pollution at the bottom of the tank, the pressure of the cylinder is generally required to be greater than 3MPa to prevent pollution at the bottom of the tank.

2. System instability or leakage: After the temperature reaches equilibrium, eliminate the leakage.

3. amplifier fault: amplifier repair.

4.TCD component failure: replace TCD component.

5. Fixed liquid loss or not aging: reduce the column temperature, aging column or replace the column.

The 2. baseline is noisy.

1. No purification or pollution of the gas: inspection and treatment of purification equipment.

2. The carrier gas pressure is unstable and the flow rate is too high: check and test the carrier gas flow rate.

3. Leakage: Check the leakage point and repair it.

4. Detector contamination: Clean the thermal conductivity cell or flame ionization detector.

5. The power supply of the thermoelectric detector is unstable: check the power supply voltage and switch.

6. Amplifier drift: Repair or replace the amplifier.

7. Poor line contact: clean and dry the joint with absolute alcohol, insert and tighten each terminal.

8. Poor grounding: check the grounding condition or floating.

9. Insulation of signal cable is reduced: remove the connectors at both ends of the cable and check with a megohmmeter.

10. Radiator power interference: disconnect the heating power supply and repair it after confirmation.

11. The hydrogen generator fluctuates too much during use: adjust the working current of the hydrogen generator to control the basic balance of gas production and gas use.

The 3. baseline cannot be adjusted to zero.

1. Line short circuit: eliminate short circuit.

2. Base flow is too large: eliminate gas purification, fixed liquid loss, combustion gas flow is too large and other reasons.

3. Detector distortion: detect whether the amplifier, amplifier parameters and components are normal, correct the parameters or replace the components.

4.TCD bridge arm imbalance: TCD heat transfer wire.

5.FID nozzle local blockage: eliminate blockage.

4. baseline showed S-shaped fluctuation.

1. Thermostat external insulation performance is poor, can be in the thermostat plus insulation cotton.

2. The gas chromatograph is installed in an environment with large air volume changes, and the installation position of the chromatograph can be changed.