Differences between temperature measuring instruments
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There are TE and TT in temperature measuring instrument transmitters; I’m not sure what the difference between them is – are they the same thing?
TT refers to a temperature transmitter that can transmit data over long distances. TE refers to on-site temperature indication, such as bimetallic thermometers
TT refers to a temperature transmitter, which is a secondary instrument. TE refers to a temperature sensor, which is a primary instrument, such as a platinum resistance thermometer. Field-mounted temperature indicators, such as bimetallic thermometers, are generally denoted as TG. Generally speaking, if there are not many temperature measurement points, it is necessary to use a TT to convert the TE signal into a 4-20mA signal, just like other 4-20mA signals in the DCS. This eliminates the need for RTD cards in the DCS cabinet, which is more cost-effective ； If there are many temperature measurement points, an RTD card is added to the DCS to directly introduce the TE signals into the DCS, eliminating the need for TT conversion; this is usually done for economic reasons.
Refer to the detailed specifications for textual codes in the standard \"Instrument Symbols and Signs\" shb-z02-95.
I work in a design firm. In the flowcharts I deal with, TI refers to local temperature sensors, such as bimetallic thermometers. TE denotes temperature measurement elements, such as thermal resistors and thermocouples. TT represents temperature sensors that are used in conjunction with thermal resistors and thermocouples to convert signals into standard 4–20 milliampere signals, which are then sent to devices like PLCs and DCS systems for purposes of interlocking, alarm generation, monitoring, and control
An additional function of the temperature transmitter is the ability to indicate short circuits or open circuits; it outputs 4mA in such cases. Moreover, SH3005-1999 stipulates that \"when the temperature sensing element is a thermocouple, the temperature instrument should be equipped with a thermocouple break protection mechanism.\" However, the temperature transmitters I’ve seen that have such a protection mechanism are all installed in control rooms. Do integrated temperature transmitters possess this function as well?
Among temperature measurement instruments, there are TE and TT. TE is the temperature sensing element, while TT is the temperature converter (transmitter). TT is usually a thermal resistor or thermocouple, etc.; it functions as a temperature transmitter. Typically, TE is connected to TT, and through temperature conversion, an electrical signal of 4–20mA is generated and sent to the DCS system, thereby enabling detection and control.
Take a look at “Gauge Symbols and Signs”
TI should refer to a temperature display, such as a digital display instrument or a moving-coil display instrument, and not to on-site indicating instruments like bimetallic thermometers or pressure-type thermometers.
TT refers to a temperature transmitter, which is a secondary instrument. TE refers to a temperature sensor, which is a primary instrument, such as a platinum resistance thermometer. Field-mounted thermometers, such as bimetallic thermometers, are generally denoted as TG
There are several different opinions upstairs, which have left me confused. In fact, I think the opinion from the 10th floor is correct. This post was last edited by feiyang_ll on 2007-12-31 at 18:32.]
I don’t quite understand; I’m learning from everyone*.
Different people have different views; what some say makes sense to them, but it’s not entirely comprehensive or clear.