Panametrics DigitalFlow XMT868i, Startup Manual, Page: 12 / 94

Chapter 1. Installation
4 DigitalFlow™ XMT868i Startup Guide
1.5 Installing Temperature Transmitters
Optional temperature transmitters may be installed as part of the flowcell, near the ultrasonic transducer ports. Be
sure to observe the siting requirements given earlier in this chapter. These transmitters should send a 0/4-20 mA
signal to the Model XMT868i. In turn, the XMT868i must be fitted with a suitable option card to process the signals and
to provide the required 24 VDC power to the transmitters. Any desired transmitters or sensors may be used, but they
must have an accuracy equal to 0.5% of the reading or better.
Note: Resistive Thermal Devices (RTDs) are a good choice for measuring the temperature.
Typically, a 1/2” NPT female threaded port is used to mount the transmitters on the flowcell. If the pipeline is insulated,
the coupling may need to be extended to provide convenient access. Of course, other types of mounting ports,
including flanged ports, may be used for the transmitters.
Figure 2 shows a typical mounting arrangement for a temperature transmitter. The temperature transmitter should
protrude 1/4 to 1/2 way into the pipe.
Figure 2: Typical Temperature Transmitter Mounting
Transmitter
RTD
Coupling
Thermowell
Flowcell Wall
Temperature