Product Description

Model MPT261 melt pressure transducer or transmitter (MPT) is developed from the MPT160 sensor to measure both pressures and temperatures of melt medium of high temperatures (up to 400 °C). Employing metal foil strain gauge (MfSG) from BCM SENSOR as its sensing element, the MPT261 sensor has its wetted parts and housing made from stainless steel (SS) in order to comply with the requirements of pressure medium of high temperatures and harsh working environment. As a result, the MPT-series sensors find their applications on injection moulding machines and extruders to monitor or measure both the pressures and temperatures of working medium in melt state.

Compared to MPT260, the MPT261 has additionally integrated with a thermocouple or Pt100 as a temperature sensor, the electrical interface of which is located next to the electrical interface of pressure measurement, in order to measure the temperatures of melt medium.

An SS isolation diaphragm is located at the front end of the rigid stem and will be directly approached by melt pressure medium in applications. To avoid mechanical scratches, a specially designed alloy-coating is applied on the isolation diaphragm. Inside the rigid stem, there is a capillary filled with nontoxic liquid-metal alloy which is not mercury and is able to truly transfers the medium pressure from the isolation diaphragm to an SS pressure diaphragm. The SS pressure diaphragm is located at the rear end of its rigid stem. On the backside of this pressure diaphragm there is a full bridge MfSG to convert deformation of the pressure diaphragm, which is induced by the measured pressure, into an electrical signal in millivolt.

To meet different requirements in applications, the MPT261 sensors can offer various types of output signal for pressure measurement. The standard output signal of pressure measurement can be either 3.33mV/V (i.e., the MPT261 without sensor signal conditioner (SSC)), or 4~20mA, 0~5V or 0~10V (i.e., the MPT261 integrated with SSC). By integrated with other kind of SSC, different output signals can be available, such as 4~20 mA with HART protocol, CAN-bus or modbus protocol. The output signal of temperature measurement depends on the selected type of temperature sensors which can be J-, K- or E-type thermocouple, or Pt100 thermal resistor.

To facilitate the calibration on site, the MPT261 sensors are provided with internal 80%fs shunt calibration function. By means of this function the sensors can be calibrated any time without calibrating pressures. On request the MPT261 can be integrated with a replay for control purpose.

Additional Information