1. First, turn on the power, the instrument will perform self-calibration first, and after self-calibration, it enters the measurement state.
2. While the instrument is self-calibrating, connect the test pipeline provided with the instrument to the switch connector of the switch to be measured, and then connect the switch connector to the switch under test.
3. Close the flow regulating valve, connect the test pipeline to the air inlet of the instrument, and the pressure displayed on the screen is the gas pressure inside the switch under test.
4. Start measurement, open the flow regulating valve, adjust the flow to about 0.5 L/min, and do not exceed 0.8 L/min at most, then it enters the measurement state. The measurement time is about 8 minutes (for the first device).
5. When the measurement is finished, if you need to print the data, just press the print key, enter the device number to be measured, then press the confirm key, and the instrument will start printing. Finally, close the flow regulating valve, remove the test pipeline from the instrument air inlet, and finally remove the switch connector.
6. Turn off the power. Put the test pipeline and switch connector away, and the entire measurement is complete.
Usage Precautions
●The instrument should be placed in a safe position to prevent falling and avoid severe vibration.
●Do not measure corrosive gases.
●The probe should be cleaned and calibrated after a certain period of use, with a calibration interval of one year. When calibration is needed, please contact our company.
●When adjusting the gas flow, the needle valve should be opened slowly so that the flow indication is 0.5-0.6 L/min. If the flow exceeds 1 L/min, the LCD will display a warning that the flow has exceeded the limit, and the flow should be reduced to the specified value. (Excessive flow will damage the electronic flow sensor).
●After using the instrument for one day (using battery), it should be charged promptly. When charging, just connect the power cord to a 220V socket without turning on the power switch. The instrument will charge automatically, and the charging time is generally more than 5 hours.
Importance of Moisture Measurement
Moisture is an important factor affecting insulation aging. Excessive water content can reduce the insulation performance of insulating materials and accelerate their aging, thereby reducing the reliability of operating equipment and shortening its lifespan.
Main sources of moisture inside electrical equipment:
(1) External intrusion: caused by improper protective measures during manufacturing, transportation, and installation of equipment.
(2) Self-generation: moisture produced by the oxidation and cracking of insulating media during equipment operation.
For hydrogen-cooled units, high hydrogen humidity is one of the main factors affecting the safe operation of generators. With the continuous commissioning of large-capacity, high-parameter units, multiple serious accidents have occurred domestically where generator units were burned due to hydrogen humidity exceeding standards. Traditional hygrometers can no longer ensure accurate parameter measurement to guarantee safe equipment operation, and cannot meet the needs of the power system.
Micro Moisture (Humidity) Measurement Methods
◆Measurement of SF6 Gas Humidity
For measuring SF6 gas humidity, common methods include the gravimetric method and the coulometric electrolysis method. The first method has high requirements for environmental conditions and takes a long time to measure, generally used only for arbitration analysis; the second method consumes a large amount of gas during measurement, requires the equipment to be powered on for drying all year round when not in use, and has poor repeatability.
◆Measurement of H2 Humidity
Common measurement methods include the ventilated wet and dry bulb method and the coulometric electrolysis method. The first method is greatly affected by ambient temperature and humidity, resulting in higher measured values; the second method, in addition to the aforementioned disadvantages, is also susceptible to contamination, etc.
