Accurate measurement readings require compensating for the pressure of the measured
process. MGP260 series probes do not measure pressure, meaning that it is mandatory to set
up a pressure compensation input source. The following pressure input options are
available:
- Pressure measurement received from an
external pressure measurement instrument through the Ex ia (4–20 mA) input terminals on
the MGP260 component board. This is the recommended option: for an example, see Figure 1. The wiring of the external pressure instrument input is shown in
Figure 1.
Note that the Ex ia input of the MGP260 series probes is internally powered and isolated. Compatible Ex ia pressure instruments can be directly connected to the MGP260 input terminal. - The external pressure instrument connected to MGP260 must output 4–20 mA and use absolute pressure units. The default range for the input is 1 … 1.6 bar(a).
- Pressure measurement received from a Modbus master through a serial line connection.
- If the process pressure is constant, a fixed pressure compensation value can be configured into use.
The pressure compensation input settings (for example, input type selection and input scaling) of MGP260 must match the pressure input source used in your application. For more information and configuration instructions on pressure compensation, see Environmental compensation overview.