HSMD-III SF6 gas density relay calibrator
Technical parameters
I. Instrument overview
SF6 gas density relay is an important component used to monitor the change of SF6 gas density in the SF6 switch body during operation. The SF6 gas density relay in operation on site is not often operated. After a period of time, it often has phenomena such as inflexible operation and poor contact of contacts. Some density relays also have poor temperature compensation performance. When the ambient temperature changes suddenly, the SF6 density relay often malfunctions. Therefore, DL/T596-1996 "Preventive Test Procedures for Power Equipment" stipulates that each SF6 switch user should regularly calibrate the SF6 gas density relay.
The SF6 density relay calibrator is developed based on the "DL/T259-2012: Sulfur Hexafluoride Gas Density Relay Calibration Procedure" issued by the National Energy Administration.
1.1 Product Introduction
The SF6 gas density relay uses a 7.0-inch color LCD touch screen for human-computer interaction, which is more convenient to operate. Built-in large-capacity rechargeable lithium battery pack provides ultra-long standby time. Equipped with a standard USB interface, historical data can be exported to a USB flash drive through the interface.
In addition to calibrating the SF6 density relay, the instrument also has the function of calibrating the pressure gauge and density gauge. The instrument can automatically detect abnormal conditions during the measurement process. If there is a pipeline leak, gas leakage, and insufficient inlet and outlet pressure, the instrument will automatically stop running and pop up a warning.
In a closed container, the SF6 gas pressure at a certain temperature can represent the density of SF6 gas. It is customary to take the SF6 gas pressure at 20℃ as the standard value. During on-site calibration, at different ambient temperatures, the measured pressure value must be converted into its corresponding pressure value at 20℃ to judge the performance of the SF6 density relay.
1.2 Terms and Definitions
Lockout recovery value verification: Under ambient temperature, when the SF6 density relay is at zero pressure, the SF6 density relay is slowly inflated at a certain speed. When the lockout relay of the SF6 density relay is activated, the pressure value at the current ambient temperature is recorded and converted into an equivalent pressure value at 20°C. This equivalent pressure value at 20°C is the lockout recovery value of the SF6 density relay.
Alarm recovery verification value: Continue to slowly inflate the SF6 density relay at a certain speed. When the alarm relay of the density relay is activated, record the pressure value at the current ambient temperature and convert it into an equivalent pressure value at 20°C. This equivalent pressure value at 20°C is the alarm recovery value of the SF6 density relay.
Overpressure alarm verification value: Continue to slowly inflate the SF6 density relay at a certain speed. When the rated pressure exceeds a certain set value and the overpressure alarm relay of the density relay is activated, record the pressure value at the current ambient temperature and convert it into an equivalent pressure value at 20°C. This equivalent pressure value at 20°C is the overpressure alarm verification value of the SF6 density relay.
Alarm value verification: Under ambient temperature, when the pressure in the SF6 density relay is greater than the alarm response value, the gas is slowly released at a certain speed. When the alarm relay of the SF6 density relay is activated, the pressure value at the current ambient temperature is recorded and converted into an equivalent pressure value at 20°C. This equivalent pressure value at 20 degrees is the alarm value of the SF6 density relay.
Locking value verification: Continue to slowly release the SF6 density relay at a certain speed. When the locking relay of the SF6 density relay is activated, the pressure value at the current ambient temperature is recorded and converted into an equivalent pressure value at 20°C. This equivalent pressure value at 20°C is the locking value of the SF6 density relay.
1.3 Types and zero positions of density relays
1.3.1 Absolute pressure type density relay
Absolute pressure type density relay: A gas density relay with absolute pressure as the indicator and absolute vacuum as the reference pressure.
1.3.2 Relative pressure type density relay
Relative pressure type density relay: A gas density relay with relative pressure as the indicator and ambient atmospheric pressure as the reference pressure.
1.3.3 Relative mixed pressure density relay
Relative mixed density relay: a gas density relay with relative pressure as the indicator and standard atmospheric pressure as the reference pressure.
1.3.4 Absolute mixed pressure density relay
Absolute mixed pressure density relay: a gas density relay with absolute pressure as the indicator and ambient atmospheric pressure as the reference pressure.
1.3.5 Zero position
The position of the pointer of a density relay with a scale starting from a positive pressure value and with a stop pin under pressure-free conditions, when the ambient temperature is 20℃ and the atmospheric pressure is standard atmospheric pressure, before the pressure increase calibration and after the pressure reduction calibration.
1.3.6 Density relay type identification
For density relays whose scale starts from the lowest pressure value, under no-pressure conditions, before the boost calibration and after the drop calibration, the pointer zero position should meet the following conditions:
Absolute pressure density relay: When the ambient temperature is 20℃, the pointer must point to the local atmospheric pressure value; when the ambient temperature is higher than 20℃, the pointer should point to a position below the local atmospheric pressure; when the ambient temperature is lower than 20℃, the pointer should point to a position above the local atmospheric pressure;
Relative pressure density relay: When the ambient temperature is 20℃, the pointer must point within the zero position graduation line width; when the ambient temperature is higher than 20℃, the pointer should point to a position below the zero position; when the ambient temperature is lower than 20℃, the pointer should point to a position below the zero position. , the pointer should point to the position above zero;
Relative mixed pressure density relay: when the ambient temperature is 20℃, the pointer must point to the difference between the current ambient atmospheric pressure and the standard atmospheric pressure; when the ambient temperature is higher than 20℃, the pointer should point to the position below the difference; when the ambient temperature is lower than 20℃, the pointer should point to the position above the difference;
Absolute mixed pressure density relay: when the ambient temperature is 20℃, the pointer must point to the 0.1MPa graduation line width range; when the ambient temperature is higher than 20℃, the pointer should point to the position below the 0.1MPa graduation line; when the ambient temperature is lower than 20℃, the pointer should point to the position above the 0.1MPa graduation line.
2. Main features
1. The density relay calibrator adopts high-performance single-chip microcomputer for detection and control, and the core components adopt imported components, with high precision, good repeatability and high reliability.
2. Equipped with a color touch LCD screen, it is easy to operate, beautiful interface, and all parameters and status are clear at a glance.
3. Automatically complete pressure measurement and 20℃ value conversion, thereby completing dynamic automatic compensation between pressure and temperature. And display the pressure at the measured ambient temperature, the pressure at the ambient temperature of 20℃, and the ambient temperature. Completely solve the problem of difficult on-site calibration of SF6 gas density relay.
4. All test processes are automatically completed by the single-chip microcomputer without manual intervention, avoiding cumbersome manual gas circuit adjustment operations.
5. It can store 40 test results at the same time, and has power-off data protection function, and can query and print previous test results at any time.
6. No constant temperature room is required during the calibration process, and the SF6 gas density relay and pressure gauge can be calibrated within any effective temperature range.
7. Equipped with a variety of transition joints, the density relays of most models of switches can be calibrated on-site without disassembly.
8. In addition to the density relay calibration function, this instrument also has 20℃ pressure gauge calibration and normal temperature pressure gauge calibration functions.
9. The gas cylinder pressure reducing valve is professionally designed, with a pressure resistance of 15MP (150 kg), and the low-pressure output is adjustable, which is suitable for calibration of metering rooms with nitrogen as the test gas.
3. Technical parameters
Verification object: Alarm 1, Alarm 2, Lock 1, Lock 2, Overpressure alarm contact signal
Verification range: 0~1Mpa (absolute pressure)
Instrument accuracy: 0.1 level
Repeatability: ±%F.S at 20℃
Pressure display resolution: 0.001MPa
Inlet pressure: 0.9~1MPa (relative pressure)
External interface: USB (supports USB mobile storage devices not larger than 4GB)
Working environment: Temperature -10~50℃ (optimal operating temperature 5~50℃)
Relative humidity 5～90%RH
Display resolution: 800×480 (pixel) color touch screen
Storage capacity: 40 groups
Measurement contact voltage: DC24V
Temperature acquisition method: manual/automatic
Inlet connection: φ4 docking quick plug
Inlet pipe: standard φ4/PFA pipe
Measurement connection: φ4 docking quick plug
Measurement pipe: standard φ4/PFA pipe
Exhaust connection: φ4 quick plug connector
Exhaust pipe: standard φ4/PFA pipe
Mobile power supply: rechargeable lithium battery pack, can work continuously for 8 hours
Charging voltage: 100～240VAC, 50/60HZ
Working voltage: 14.8V DC
Main body dimensions: 325mm long×275mm wide×140mm high
Accessory box dimensions: 360mm long×250mm wide×110mm high
Instrument weight: 4.5Kg
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