The explosion-proof pressure sensor is an intelligent digital display pressure sensor that integrates pressure measurement, display, output, and control. Its performance and characteristics are as follows:
The principle of explosion-proof pressure sensors is basically the same as that of ordinary pressure sensors. The pressure of the measured medium is transmitted to the explosion-proof transmitter through a connecting joint. The measuring head is a component that can change capacitance. Due to the pressure, the capacitance of the measuring head changes with the pressure. The changing capacitance output from the measuring head is transmitted to the oscillator of the oscillating plate. The oscillator changes the oscillation frequency according to the changing capacitance. The changing oscillation frequency signal is amplified by integrated operation and detection, and outputs a half-wave signal with a lower oscillation frequency. This signal is then sent to the intelligent microprocessor.
The explosion-proof pressure sensor housing features an isolated explosion-proof design, intrinsically safe explosion-proof circuitry, signal isolation amplification, frequency cutoff interference design (anti-interference, lightning protection), overvoltage protection, current limiting protection, impact resistance, corrosion resistance, and a compact and portable design. It is made of fully welded 316 stainless steel, with a small and compact structure, good moisture resistance, and excellent media compatibility.
To address common issues such as errors, signal interference, and no signal in the use of explosion-proof pressure sensors, the following solutions have been derived based on years of experience:
1. The pressure reading is unstable or incorrect.
1. Check if the power supply of the explosion-proof pressure sensor is normal. If it is less than 12VDC, check if there is a large load in the circuit. The input impedance of the pressure sensor load should meet the requirement of RL≤(pressure sensor power supply voltage-12V)/(0.02A)Ω.
2. The input impedance of the pressure sensor load should meet the requirement that RL≤(pressure sensor power supply voltage-12V)/(0.02A)Ω. If it does not meet the requirement, corresponding measures can be taken according to the specific circumstances, such as increasing the power supply voltage (but it must be lower than 36VDC) or reducing the load.
3. Check if the input of the pressure indicator and the corresponding wiring are correct. If the input of the pressure indicator is 4~20mA, the output signal of the pressure sensor can be directly connected; if the input of the pressure indicator is 0-10V, the pressure indicator must be adjusted to the corresponding input.
4. Check whether the range of the pressure indicator is consistent with the range of the explosion-proof pressure sensor and connect it to a resistor with an accuracy of 0.1% or higher and a resistance of 250Ω before connecting it to the input of the pressure sensor.
5. If the input terminal of the multi-point paper recorder is open when there is no recording, then: 1. Do not connect any other loads; 2. Use another recorder with an input impedance ≤250Ω when there is no recording.
6. Whether the corresponding equipment casing is grounded. The equipment casing is required to be grounded.
7. Check if the pressure sensor is damaged. Severe overload can sometimes damage the diaphragm. If damaged, it needs to be returned to the manufacturer for repair.
8. Is the pipeline temperature too high? The general operating temperature of pressure sensors is -25~85℃, but in actual use it is within -20~70℃. If the temperature is too high, a buffer tube can be added for heat dissipation.
II. Pressure sensor has no output
1. Check if the power supply to the explosion-proof pressure sensor is connected in reverse;
2. Connect the ammeter in series with the 24V power supply circuit to check if the current is normal;
3. If it has a meter head, check if the meter head is damaged. If the meter head is damaged, it needs to be replaced.
