Measured by the differential pressure transmitter is the result of the pressure difference, i.e. P = rho g h and because of the cylindrical tank often, the cross section of the area of a circle S is constant, so gravity g = P = rho g h. s. S, S, g and P is proportional to the relationship As long as accurately detect the P value, and is inversely proportional to the height h, when the temperature changes, although the oil volume expansion or shrinkage of small, practical liquid level higher or lower, detected by the pressure is always remains the same If users need to display the actual level, can also introduce the medium temperature compensation
Related parameters
Use objects: liquid gas and steam.
Measuring range :0~0.1kPa to 0~40MPa.
Output signal: 4-20ma DC(special 4-wire 220V AC power supply,0~10mA DC output)
Power supply :12~45V DC, generally 24V DC.
Load characteristics: related to the power supply power, the load capacity is shown in figure 2 at a certain power supply voltage, and the load impedance RL and the power voltage Vs relation are :RL 50(Vs 1:12).
Indicator table: pointer type linear indication 0~100% calibration or LCD liquid crystal display.
Range and zero: external continuous adjustable.
Positive and negative transfer: the upper limit value and the lower limit value of the range measurement range after positive transfer or negative transfer.
The maximum positive transfer amount of the maximum positive transfer is 500% of the minimum adjustment range.
The maximum negative transfer is 600% of the minimum adjustment range.
Temperature range: the working temperature range of the amplifier: -29~+93 (LT type: -25~+70)
The measuring element of filling silicone oil :-40~+104.
Flange type transmitter filling high temperature silicon oil :-20~+315, ordinary silicon oil :-40~+149.
Static pressure :4, 10, 25, 32MPa.
Humidity: relative humidity is 5~95%.
Volume intake :<0.16cm3.
Damping (step response): when filling silicone oil, it is generally adjustable between 0.2s and 1.67s.
Accuracy: 0.2%
Dead zone: no (0.1%)
(intelligent stability: six months for one year) shall not exceed the maximum range of the basic vibration effects of absolute value of error: in any axis, the vibration frequency of 200 hz, the error of measurement range limit of 0.05% / g
Power effect: less than 0.005%/V of output range.
Notes:
1. Do not add more than 36V voltage to the transmitter, causing damage to the transmitter;
2. Do not touch the diaphragm with hard objects, resulting in the damage of the isolation diaphragm;
3: the media is not allowed to freeze, otherwise the damage sensor element will be isolated, causing damage to the transmitter and temperature protection of the transmitter when necessary to prevent freezing.
4: when measuring the steam or other high temperature media, the temperature should not exceed the limit temperature of the transmitter, which must be higher than the limit temperature used by the converter.
5: when measuring steam or other high temperature medium, should use the radiator pipe, the transmitter and the pipe together, and use the tube on the pressure to the transformer When the measured medium is water vapor, in the radiator pipe to inject the right amount of water, in case of direct contact with the transducer of superheated steam, damage to the sensor;
6. In the process of pressure transmission, the following points should be paid attention to:
A.the connection between a transmitter and the heat pipe should not leak.
B.before used it, if the valve is closed, you should careful to slowly open the valve, in order to avoid direct impact sensor diaphragm measured medium, so as to damage the sensor diaphragm;
C.The pipeline must be unblocked, the sediment in the pipe will pop up and damage the sensor diaphragm. |