GE DigitalFlow DF868, Руководство для стартапов

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Chapter 1. Installation
4 DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Startup Guide (1- and 2-Channel)
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 must use a 0/4-20 mA signal to
transmit the temperature values to the Model DF868 electronics console. In turn, the electronics console will provide a
24 VDC signal to power 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. If you use direct RTD
inputs, you do not require transmitters.
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 the pressure and temperature transmitters. The temperature sensor
should protrude 1/4 to 1/2 way into the pipe.
Figure 2: Typical Temperature Transmitter Mounting
1.6 Mounting the DF868 Electronic Console
The standard Model DF868 electronics package is housed in a NEMA-4X weather-resistant enclosure. Refer to
Figure 9 on page 15 for the mounting dimensions of this enclosure. For meters housed in one of the optional
enclosures, a dimensional drawing will be shipped with the unit.
IMPORTANT:
For meters supplied in one of the optional enclosure styles, refer to Appendix C, Optional Enclosures ,
for specific mounting dimensions and instructions.
WARNING! Proper grounding of the DF868 chassis is required to prevent the possibility of electric shock.
See Figure 10 on page 16 to locate the internal ground connection.