Industrial temperature sensors are either thermocouples or RTDs that are inside of a sheath of stainless steel or Inconel which is inserted either directly into the process or into a thermowell which is inserted into the process.
Either can be connected to an analog input specifically designed as either a thermocouple input or an RTD input; either has special requirements that are not compatible with voltage only analog inputs.
It is common to connect either sensor to a 'transmitter', which converts the sensor signal to 4-20mA, which is the most common industrial analog signal interface in the process world. A transmitter needs DC power from a DC power supply. Some are 2-wire with a power supply in series in the loop, others are 3 or 4 wire, with either a shared wire or independent wires for power and signal.
100 Ohm DIN is a worldwide standard for RTDs, but 600 Deg C approaches the top limit for an RTD. Always use a 3 wire RTD, 2 wire RTDs have inherent offset error due lead wire length. 4 wire are for lab use only. RTDs are more delicate than thermocouples.
Without knowing more about what you're trying to accomplish, I'd start by looking at a thermocouple, Type K.
A thermowell does create a temperature response lag (time), but keeps the process contained if the sensor element needs to be removed for calibration or replacement.
For mechanical temperature indication there are bimetallic thermometers that insert into wells or direct with a round dial. There are also bulb and capillary thermometers with an indicating dial, but those get more expensive year.
There are no direct connect pressure transmitters that can tolerate the temperature of your process. The meter body of an industrial pressure transmitters are generally rated to about 125 Deg C. Heat kills electronics.
The technique is to either
- use an impulse tube with the pressure transmitter at the end of the tube. Urban legend says a 0.3m drops 50 Deg C, but my experience shows that 0.5 m will drop almost any survivable temperature. An impulse tube is dead headed, meaning there's no flow through the tube. The implication is that one can never bleed or vent through the impulse tube because the flow of hot gas will provide sufficient heat to destroy the transmitter.
- use a remote seal. The seal mounts to the process with one of dozen different styles, or can mount on the end of length of impulse tubing. A length of capillary tubing (very small diameter, looks like wire) provides distance from the hot seal to the transmitter, which keeps the transmitter cool. The seal/capillary/transmitter is a filled system (like the mechanical thermometer) where the fill fluid transfers the pressure from the seal diaphragm to the transmitter sensor. It requires special equipment and skill to put it all together so remote seals are sold as assemblies.
This kind of stuff is sold through distributors (middle men who buy from the manufacturers).
Google pressure transmitter and your local city or state and see who comes up. Call a coiuple and explain what you're looking for and see who is the most knowledgeable. Be wary of those who can only ask "what part number to you need?" because they're revealing their inability to helping select an appropriate product.
