GC-7890MD gas chromatograph is a new generation of power system dedicated gas chromatography manufactured by Chongqing TOP Oil Purifier Co., Ltd. for the power industry. The instrument uses advanced computer control system and large-screen Chinese / English display, which is in strict accordance with three detector flow recommended by the national standard GB / T 17623-1998 "Dissolved gas component content in insulating oil by using gas chromatograph method", GB / T7252-2001 " Guide for interpretation of dissolved gases in oil-immersed transformer ". Advanced thermal conductivity amplification technology to increase 10 times of the detection capacity of hydrogen. High-sensitivity micro-current amplifier circuit made the ability of detecting hydrocarbon gases rise to limit. Excellent column system ensures good chromatographic peak shape and the best resolution. Stable gas control system ensures the accuracy and repeatability of the analysis.

Instrument uses computer control, keyboard-type operation and LCD screen display, with advantages of high integration of electronic circuits, good reliability, simple operation, long-term operation and so on.

The instrument is equipped with a thermal conductivity detector, dual hydrogen flame detector and nickel converter. Seven (or nine) kinds of gas components in oil sample can be achieved with automatic total analysis at a time;

The oven is equipped with a rear door automatic cooling system. Each heating zone (the capillary injector incubator, detector incubator, auxiliary incubator, oven thermostat) is separated from each other by a heat insulating material, so that the heat conduction between the heating zones is minimized and the temperature of each heating zone can be independently controlled.

The gas flow and pressure control system of instrument is installed inside the instrument gas-line box. The injection system installed at the top of the instrument requires vertical injection.

Instrument signal output can be connected to the transformer oil chromatography data processing system, integrator, computer and other peripheral drawing equipment.

Instrument technical index

2.1 Comprehensive parameters

1) Dimensions: 565 * 505 * 500mm]; (length * height * width)

2) Packing box dimensions: 730 * 650 * 610 [mm]; (length * height * width)

3) Column spacing size: 150mm

4) Column: two dedicated chromatography column

5) Instrument weight: 65Kg

2.2 Temperature control index

Oven temperature control:

1) Room temperature plus 6 °C ~ 399 °C; (in increments of 1 °C),

(set effectively parameter up to 399 °C, allowing using but not to guarantee the technical index)

2) Temperature fluctuation: no more than ± 0.1 °C; (ambient temperature change 10 °C or power supply voltage change 10%).

3) Temperature gradient: ± 1% (temperature range 100 °C ~ 350 °C).

4) Program heating step: 7 step

5) Heating rate: 0 ~ 40 °C / min (set in increments of 0.1 °C).

6) Cooling rate: not more than 3 min when oven cool from 200 °C to 100 °C

7) Time setting: 6000 (min)

Thermal conductivity detector temperature control

Room temperature plus 20 °C ~ 350 °C (index parameters).

(Set parameters: room temperature plus 6 °C ~ 399 °C effective, allowing using but not to guarantee the technical index ).

Temperature control accuracy: not more than ± 0.1 °C.

The remaining heating zone temperature:

Room temperature plus 20 °C ~ 350 °C (index parameters).

(Set parameters: up to 399 °C effective, allowing using but not to guarantee the technical index ).

Temperature control accuracy: not more than ± 0.2 °C.

2.3 FID detector

Detection limit:≤8*10-12g/s(n-C16H34)

Noise: ≤ 2 * 10-14A(0.02mv)

Drift: ≤ 1.5 * 10-13A / 30min(0.15mv/30min)

Dynamic linear range: ≥ 107

2.4 TCD detector

Sensitivity: ≤5000mv.ml/mg(n-C16H34)

Noise: ≤2*10-14A (0.02mv)

Drift: ≤1.5*10-13A/30min (0.15mv/30min)

Dynamic linear range: ≥ 104

2.5 Application Environment

Ambient temperature: (5 ~ 35) °C

Relative humidity: no more than 85%

Power Supply voltage: 220 ± 22V

Power supply frequency: 50 ± 0.5Hz.

Maximum power consumption: 2500W

No Indoor corrosive gases. No strong mechanical vibration on table. No strong electromagnetic interference nearby. No dramatic indoor temperature change. No air convection