Selection of thermal resistors
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This post was last edited by zxb1990 on 2017-1-3 at 22:31. The 7.1.1 thermocouple/thermistor assembly shall include a thermosensitive element, a protective sleeve, short connectors, and thermocouple/thermistor terminals, and they shall be designed in accordance with ANSI MC 96.1 requirements. The thermistor cannot be connected to the heat sleeve. All thermocouples/thermoresistors are dual-wire. All thermocouples and thermal resistors shall have a vibration-damping spring structure. The protective sleeve is of the integral drilling type, and the connection method depends on the pressure, temperature, and flow rate of the fluid being measured. - For all field instruments, the enclosure is made of stainless steel S30408. For all electronic field instruments, the cable entry should be 1/2” NPT (F). - The enclosure protection rating is not lower than IP65. - Copper, aluminum, brass, or their alloys are not allowed to be used as any components. 1) Temperature instrument: A remote-transmission temperature instrument; for a measurement range of -200~500℃, a Pt100 platinum resistance thermometer is used ； All temperature elements should be fitted with thermometer sleeves. The outer diameter of the sleeve is φ16mm, and its material must meet the requirements of the process medium. The above documents outline the requirements for selecting instruments; I need guidance on how to choose thermistor temperature sensors
The above documents outline the requirements for selecting instruments; I need guidance on how to choose thermistor temperature sensors
1. The housing is made of stainless steel; in my understanding, this refers to armored thermoresistors. Generally, if the wiring box is required to be explosion-proof or similar, it also needs to be made of stainless steel or aluminum. 2. For the cable entry, it depends on the outlet of the junction box; there’s no major issue. 3. The protection rating of IP65 applies to the junction box. 4. That’s a bit too strict; as a sealing element, it’s highly desirable to use copper gaskets, although stainless steel gaskets can also be used, though at a higher cost. Additional note: 1. It is not specified whether the dual-element thermoresistors use a three-wire or four-wire system; three-wire systems are more common generally. Of course, if they are to be used as control signals, a dual-element four-wire system is more reliable. 2. If the range is from -200 to 500, it is likely that a platinum resistor from a certain German brand will not be suitable for use; hence, no advertising can be done for it :D 3. The type of sleeve can also be straight or tapered, depending on the specific application area.
You can contact me; I’ll help you choose. If needed, you can add my QQ number – that’s my name there
It seems that one needs to consult the manufacturer regarding how to select the appropriate model.
Is it about me? :$ Also, in reply to lz, it seems that the ANSI MC 96.1 standard is no longer in use; this specification seems to have been passed down from generation to generation: lol
Based on the requirements you mentioned, a thermocouple temperature sensor with a heat-shielded probe should be chosen
Different manufacturers have their own rules regarding model specifications; you just need to select a model that meets the required standards
This is a screenshot of a PT100 resistance sensor sample from Chuanyi
Let me put it this way: these days, state-owned enterprises mostly rely on assembly processes, and it’s best to stay away from temperature instruments produced by such enterprises.