The CNPS-MT-B11 type drilling fluid temperature sensor is composed of a temperature detector and a transmitter. When the drilling fluid temperature changes, the resistance of the temperature sensor in the temperature sensor detector changes correspondingly, and the change is linear with the temperature change. The transmitter converts the resistance change to 4-20 mA standard DC current signal.
Power supply: +15V to 30V DC (recommended +24V DC)
Measuring range: 0~100 C
Output current: 4 ~ 20mA DC
Measurement accuracy: + 1.0%FS
Environmental conditions: the working temperature of the sensor is between -40 and +85 C.
Relative humidity: 5 ~ 95%RH
3.1 sensor installation
CNPS-MT-B11 mud temperature sensor is very convenient to install. It is only necessary to immerse the sensor temperature sensor in the drilling fluid to be measured completely, then fix it with a bracket and connect it with a cable.
3.2 sensor wiring
Open the cover of the sensor sealing box, connect the’+’terminal to the + 24V power supply, and connect the’- terminal signal as shown in Figure 1.
Figure 1. Temperature sensor wiring diagram
4 Sensor calibration
CNPS-MT-B11 drilling fluid temperature sensor has been strictly adjusted at the time of leaving the factory, generally does not require on-site adjustment. If there are problems with sensors, they need to be adjusted on-site, using precision resistance boxes. The adjustment method is shown in Figure 2.
- Open the cover of the sensor sealing box, remove the wiring on the 1, 2, 3 terminals, and connect the transmitter, precision resistance box, multimeter and power supply as shown above. (2) Adjust the resistance value of the precision resistance box to 100_and observe the change of the output current value of the sensor. The current value should be 4 mA at this time. If the display value deviates greatly, the zero potentiometer of the transmitter should be adjusted so that the output current value of the sensor is 4 mA.
(3)Adjust the resistance value of the precision resistance box to 138.5_and observe the change of the output current value of the sensor. The current value should be 20 mA at this time. If the display value deviates greatly, the gain potentiometer of the transmitter should be adjusted so that the output current value of the sensor is 20 mA.
- the transmitter part must be sealed to prevent water from damaging the transmitter.
- the mud should be adhered to the temperature sensor and should be cleaned in time to ensure the reliable and accurate operation of the sensor.
- When the temperature sensor is in use, it should check whether the cable is broken, short circuit and the connection head is off.
(4) Temperature sensor fault, can be used multimeter resistance to measure the Pt100 thermistor lead both ends, there should be 100-140_between the resistance, otherwise check whether the sensor is open or the connection of the Pt wire is not good contact.