ASME B40.200-2008 pdf – Thermometers, Direct Reading and Remote Reading
ASME B40.200-2008 pdf – Thermometers, Direct Reading and Remote Reading.
temperature, ambient: the temperature of the medium surrounding the indicating head and capillary. Temperature at the capillary may be different from the temperature at the indicating head.
temperature compensation: see corn pensation, full and corn— pensatwn, nidicating head.
temperature, process: the temperature of the process medium.
temperature, storage: the extremes of temperature (high and low) that the thermometer may be exposed to when stored, transported, or not in use.
thernial system: the portion of a thermometer consisting of the bulb, extension (if provided), capillary, elastic element, and the fill medium.
thermometer, direct reading: a thermometer with the indicating head connected directly to a rigid extension (see Fig. 3).
thermonzeter,flusli inou ii fed: a thermometer provided with supporting means on the indicating head so that it may be set in a panel. When installed, the dial is approximately flush with the panel (see Fig. 5).
theri;ioi;ietei re’inote reading: a thermometer with the indicating head connected to the bulb with capillary (see Fig. 3).
thermometer, surface (wall) mon ii ted: a thermometer whose indicating head can be mounted to a wall or flat surface (see Fig. 5).
thermometer, tern perat U re compensated: a thermometer that is compensated to reduce errors during operation at ambient temperatures other than that at which it was calibrated.
thermowell: a pressure-tight receptacle adapted to receive a bulb and provided with external threads or other means for pressure-tight attachment to a vessel or system.
threaded ring: see ring, threaded.
traceability, calibration: documentation of the existence of a calibration chain between an instrument and the National Institute of Standards and Technology (formerly the National Bureau of Standards).
true value: the value of the parameter being measured as determined by an accepted calibration standard after all corrections have been made.
it muon—connected bulb: see bulb, ii iiion COil nected. well: see thermowell.
window: a transparent component through which the dial is viewed
window, heat-treated glass: a window of heat-treated (tempered) glass, that, when broken, will form small, granular pieces, usually with no jagged edges.
window laminated glass: a window with two or more sheets of glass held together by an intervening layer(s) of clear plastic. When cracked or broken, the pieces of glass tend to adhere to the plastic.
windozo, plani glass: a window of commercial glass. window, plastic: a window of transparent plastic.
window, threaded: a window generally made of plastic with integral threads that match threads on the case. No separate ring is required.
4.1.1 Before mstalling a thermometer, consideration should be given to ambient temperature, humidity, vibration, shock, and other climatic and ambient conditions of the service application (see Safety, section 6).
4.1.2 The bulb may be installed directly into the medium (see Safety, section 6).
4.1.3 The filled system of the thermometer is a sealed unit and must remain sealed. The capillary should be kept coiled until installation to avoid sharp bends or kinks.
4.1.4 A thermometer can be rendered inaccurate during shipment despite care taken in packaging. To ensure conformance to the accuracy grade to which the thermometer was manufactured, it should be checked before use (see Test Procedures, section 8).
4.2 Installation Procedure
4.2.1 Placement. The bulb should be located and completely immersed at the point that will provide temperature indication that is most representative of the process. Adequate circulation of the medium is necessary for optimum response and accuracy.
4.2.2 Direct Reading Thermometer. Use the wrench flats, when provided, to install the thermometer.
4.2.3 Remote Reading Thermometer. Do not twist, kink, strain, or cut the capillary. After the indicating head has been mounted, uncoil the capillary and place the bulb at its intended location.