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1. Having basic knowledge about transmitters
2. Having basic experience about transmitters
3. Having a desire

In this part the instructer explains the design criteria for selection of temperature transmitters for different applications and how a datasheet for temperature transmitter could be created.Moreover, the instructor provides examples to help you better understand the design criteria.

Overview

For process temperature up to 500 oC, as a general rule, temperature transmission shall be achieved by resistance element associated with a transmitter. Use of RTD separate amplifier and use of thermocouples shall be restricted to machines and heaters. RTDs and thermocouples shall be ground insulated type. Head mounted ohm/I (RTD) or mV/I (T/C) converters shall generally be applied. The temperature detectors shall be installed in thermowells. Standard length thermowells shall be used. Process connection for thermowells shall be 1 1/2″ on pipe work up to 2500# and 2″ on lines over 2500# and on vessels.

For the measurement of fluid temperature below 0 oC, the length of the head extension shall suit the insulating thickness but the head shall extend at least 200 mm outside the insulation.
Thermowells shall be solid machined and drilled in a tapered configuration. They shall be stainless steel as a minimum, flanged type. Where the nature of fluid requires a higher alloy or other material, the thermowell material shall be consistent with the piping or equipment specification. Thermowells for test points shall be provided with plug. Where high velocity gases are present, it will be necessary to check thermowells for the “vortex shedding effect”. Where the application of thermowells would be impractical, thermocouples and resistance thermometers may be located on the surface of pipes or vessel, etc. Spring-loaded sensor shall be used. The minimum length for 4″ pipe and larger shall be approximately midway between the center of the pipe and the opposite wall, unless otherwise specified by calculated fluid velocity. Wake frequency calculation to ASME PTC 19.3 shall be produced in high velocity lines; the wake frequency shall not exceed 80% of the natural frequency of the thermowell. Calculations shall be provided for all non-standard lengths.

In this minute you get to know different types of level transmitters and the criteria by which you can select a specific type of level transmitter for a specific application.Moreover, the instructor provides examples to help you better understand the design criteria.

In this part you are taught the design criteria for pressure transmitters.Moreover, the instructor provides examples to help you better understand the design criteria.