How to choose the temperature sensor?

Temperature sensor products for various industries-From VSEC Elec.

As one of the seven basic dimensions, temperature has more than 400 years of history since the earliest measurement of temperature by humans. Whether in industrial applications or in daily life, accurate temperature measurement is an essential link. With the advancement of technology, temperature sensors have been derived.

1. The difference between temperature sensors

There are many different types of temperature sensors that can be used for temperature measurement. The most common are NTC Thermistor, Thermocouple, Platinum RTD, Digital Temperature Sensor. They have Specific operating parameters make it more suitable for an application. We will use the following table to compare the four common temperature sensors mentioned:

NTC Thermistor Platinum RTD Thermocouple Semiconductor
(digital temperature sensor)
Sensor Ceramic(metal-oxide spinel)Platinum wire-wound or metal filmThermoelectricSemiconductor junction
Temperature Range(typical)-50 to +300℃-200 to +650℃-200 to +2800℃-70 to +150℃
Accuracy(typical)0.05 to 1.5℃0.1 to 0.5℃0.5 to 5.0℃0.5 to 5.0℃
Long-term Stability @100℃0.2℃/year(epoxy)
Variable, some types very prone to aging>1℃/year
OutputNTC ResistancePTC resistance
10mV to 40mV/℃
Digital,various outputs
LinearityExponentialFairly linearmost types non-linearlinear
Power RequiredConstant voltage or currentConstant voltage or currentSelf-powered4 to 30 VDC
Response TimeFast
0.12 to 10 seconds
Generally slow
1 to 50 seconds
0.10 to 10 seconds
5 to 50 seconds
Susceptibility to Electrical NoiseRarely susceptible High resistance onlyRarely susceptiblesusceptible/cold junction compensationboard layout dependent
Lead Resistance EffectsLow resistance parts onlyVery susceptible. 3 or 4-wire configurations requiredNone over short runs. TC extension cables required.N/A
CostLow to moderateWire-wound:High

2. Select the required sensor type

When selecting the required temperature sensor, you should first consider the type of temperature sensor. The difference in sensor type directly determines the range that can be measured.

Thermistors are commonly used to measure biological environment temperature (-10 ~ 100 ℃), such as body temperature, water temperature, refrigerator, stove, etc. The small volume and fast response speed make it widely used in daily life.

Thermocouples are frequently used in the industrial field because of their wide temperature range (-200-2800 ℃) and no external power supply is needed. Common types of thermocouples include J, K, T, E, R, S, B, N, each The types of thermocouples have corresponding advantages. The most common types are J, K, and T thermocouples.

Platinum resistors are often used in laboratory environments and medical applications because of their excellent stability and accuracy (0.1-0.5 ° C), but they are the most expensive of all sensors.

The digital temperature sensor is a digital model for transmission, which is easy to collect, transmit, and analyze, and the range temperature (-70 ~ 150 ℃) is suitable for the biological environment and is widely used in the wireless transmission field.

3. Select the required installation environment

Due to the different test environment and safety factors, temperature sensors are often processed into temperature sensor probes. The sensor is packaged with different materials to ensure the stability and service life of the sensor. VSEC Elec. Will provide the most comprehensive sensor sealling solutions and products (The official website for details).