Choosing the right thermometer type and configuration for your application
To use thermometers properly, you should also know more about all the types and configurations available. This is similar to when you are choosing a laptop or smartphone, you need to think about what you need and what you can find on the market to fit those needs.
This article reviews the most common configurations of thermometers as well as discusses the pros and cons of each.
To know more about thermocouples, you can read our article on thermocouple types
To learn about the difference between temperature sensor types, read our article on RTD vs thermocouple vs thermistor
Thermometer types and configurations
MI cable probes
Mineral-insulated cable probes work well in odd or difficult spaces. If you need circular or small cables and flexible installation, then check these out.
MI cable probes can bend and wind into coils, and you can use them directly or as extension cables. They can also withstand high pressure and vibration.
- Good flexibility
- Low cost
- Good strength (although thermowells are stronger)
- Faster response than sensors with thermowells
- Moisture can cause electrical leakage
- Vibration can cause damage
- Exposure to process conditions can cause damage
Compact thermometers come into play in applications with tight spaces. Often used with RTDs, they take up little room and offer reliability with easy installation. You’ll find them most often in industries like utilities or food and life sciences.
- Size allows easy installation in small spaces
- Fast response
- Low cost
- High accuracy from 0.15 to 0.55 °C with respect to measurement span
- Susceptibility to changes in ambient temperature
- Susceptibility to the proximity of process connection
- A limited number of electrical connections (M12 plugs only)
These devices allow you to build your own sensor to suit your process. A modular thermometer needs the following parts:
- Insert – Measuring element
- Electronics – Transmitter or terminal blocks to connect the sensor to the wiring
- Head – Protection for the electronics
- Neck – Extension between head and thermowell
- Process connection – Threads, clamps or flanges to connect the sensor to the process
- Thermowell – Protection for the insert (also allows change or replacement without interrupting the process)
We also have a product review of this device.
Modular thermometers give you lots of flexibility, so you can choose the right insertion length, process connection, and electronics for your needs. You could create dozens of usable configurations. And these robust devices can operate in hazardous areas with the right connections. You’ll find them mostly in general applications.
- Flexible selection of components
- Good protection from process media
- Robust build
- Exchangeable parts
- Potentially challenging part selection
- Larger than average size
- Slow response compared to sensors without thermowells
- High cost
You’ll see ceramic thermocouples – usually types B, S, and T – in hot areas like furnaces and ovens. These devices use inserts, ceramic protection tubes, sleeves, and process connections. They can also withstand temps from 1200 to 1800 ˚C.
- High heat resistance
- Simple construction
- Decent cost
- Limited lengths
- Remote electronics
- Fragile build
- Extra work for installation (heating cycles)
To know more about this, you can also read our product review
Temperature accuracy demands precision, but one of these devices should suit your process, as long as you check your needs carefully. So, you can visit the Visaya shop to learn more about each and decide which will work best for you.
If you need help choosing the right thermometer for your application, take a look at our new temperature smart assistant.
To know more about such products, you can get in touch with our engineers!
Innovative advanced, modular RTD thermometer for use in hygienic and aseptic applications in the Food & Beverages and Life Sciences industries