A melt pressure sensor, also known as a melt pressure transducer, is a device used to measure the pressure inside an extruder barrel during the plastic extrusion process. It is specifically designed to withstand high temperatures and pressures associated with molten plastic.
Melt pressure sensor zero adjustment #
The sensor output must be rezeroed at zero pressure after installation when the machine has stabilized at operating temperature to correct for temperature effects as well as orientation, torque, side loading etc. All of these effects can be compensated for by setting the sensor zero after the machine has stabilized at operating temperature. The zero procedure is only recommended after the process temperature has stabilized, the sensor has been tightened to the specified torque and the sensor electronics housing has been permanently installed.
The mV/V sensor is normally rezeroed by the mated instrument. The mA and Voltage unit are rezeroed locally using its actuators.
Melt pressure sensor span adjustment #
Normally a zero calibration is all that is required after installation since the sensor span has been calibrated at the factory. In the event the full scale output is not correct when checked against a calibrated pressure source or dead weight tester, the sensor span can be adjusted via the span actuator. This is performed by applying a known calibrated full scale pressure to the sensor.
Melt pressure sensor calibration #
An internal calibration signal is offered for sensor to make it possible to match the sensor to the pressure indicator/controller. Calibration should be performed in pressureless state. Do not change the installed position after calibration. If the position is changed, the sensor must be re-calibrated.
Perform calibration function #
The calibration function is activated by connecting pins E & F, the sensor will simulate an applied pressure of 80% of the sensor full scale output.
Mv/v melt pressure sensor signal sensor checking #
a.when all be connected, the multimeter will show the sensor zero point ⚠️zero point should be 0.2~1.2mv/v
b. short E+F PIN the multimeter will show the sensor 80% calibration. (sensors must without any pressure)
⚠️if the mv/v sensor be connected with digital indicator, you will also have 80% calibration by press both CAL key and SET Key on indicator (only suitable for SenTec indicators. For others indicator, please refer its manual) (only suitable for mv/v sensors)
c. give the membrane some pressure by hand, to check if there are any pressure reaction.(if there are without any change on pressure, then check if the membrane probe was crushed or damaged.)
⚠️if above all are ok, then the sensors are ok without problem.
0-10V melt pressure sensor signal sensor checking #
a.when all be connected, the multimeter will show the sensor zero point
⚠️ZERO point amendment
Press the auto zero PIN once(only available for auto zero sensors) or adjust the Z point on the top of sensors (only suitable for mA, V sensors )
b. short E+F PIN the multimeter will show the sensor 80% calibration. (⚠️sensors must without any pressure)
c. give the membrane some pressure by hand, to check if there are any pressure reaction.(if there are without any change on pressure, then check if the membrane probe was crushed or damaged.)
⚠️if above all are ok, then the sensors are ok without problem.
4-20mA melt pressure sensor signal sensor checking #
a.when all be connected, the multimeter will show the sensor zero point
⚠️ZERO point amendment
Press the auto zero PIN once(only available for auto zero sensors) or adjust the Z point on the top of sensors (only suitable for mA, V sensors )
b. short E+F PIN the multimeter will show the sensor 80% calibration. (sensors must without any pressure)
c. give the membrane some pressure by hand, to check if there any pressure reaction.(if there without any change on pressure, then check if the membrane probe was crushed or damaged.)
⚠️if above all are ok, then the sensors are ok without problem.
