Temperature sensors

Temperature sensors play an important role in temperature measurement in various areas. High-quality sensors are crucial in order to achieve the desired level of precision. With our product range, we offer a wide and reliable selection of professional sensors that fulfil various needs and requirements.

Type

Type

Temperature range

Connection

Use of temperature sensors

Temperature sensors are used to measure the temperature. In conjunction with a Temperature controller can be used to monitor and control the temperature of gases or liquids. The sensors are available in resistance thermometer and thermocouple versions and convert the temperature into a measurable signal. The most common measurement methods are based on electrical resistance or electrical voltage.

Measuring principle

Resistance thermometers use the electrical resistance of metals to measure temperature. These are often used at temperatures from -200 °C to +850 °C. Resistance thermometers are particularly favoured at low temperatures, as their accuracy is higher than that of thermocouples. Thermocouples use the electrical voltage from a pair of different metals to measure the temperature and are used at high temperatures.

Measuring accuracy for temperature sensors

Standard temperature sensors are used for temperatures up to +500°C and special sensors are used for temperatures above +500°C. The sensor length should be taken into account according to the maximum immersion depth, as measurement errors can be caused by heat transfer along the thermowell. For an accurate measurement, the immersion depth of the sensor should not be less than 10 times the outer diameter. The flow velocity of the medium in which the sensor is located is also a factor that influences the measurement sensitivity. In general, R/T should be perpendicular to the direction of flow.

Designs

Depending on the application and mounting requirements, temperature sensors are available in different designs. With an immersion sensor, the sensor is encased in a thermowell. The sensor is immersed in the gas or liquid to be measured.

Bayonet probe

Bayonet sensors are fitted with a bayonet catch and a compression spring. With this fastening system, the sensor can be installed quickly and replaced quickly in the event of a defect. The installation length is set using the compression spring. Bayonet sensors are used in tools or injection moulding machines, for example.

Surface sensor

Surface sensors are equipped with a flat sensor head which is attached to a surface by means of screw mounting. These sensors are used to measure the temperature of surfaces or housing walls, for example.

Threaded probe

With a threaded sensor, the sensor head is equipped with a thread for fastening. With this type of mounting, the sensor is attached to the outside of an enclosure, for example, to measure the temperature inside the enclosure.

Angle sensor

With an angle sensor, the sensor head is arranged at a 90° angle to the fastening device. Similar to a threaded sensor, it is attached to the outside of an enclosure to measure the temperature inside. Due to the 90° angle, this temperature sensor can be installed very flat. It is attached by means of screw mounting.

Magnetic sensor

The sensor head of a magnetic sensor is magnetic. This offers the advantage of attaching the sensor to metallic surfaces without having to drill holes for screw mounting. Furthermore, the sensor with magnetic mounting can also be attached only temporarily or at different locations.

Pipe contact sensor

The sensor head of pipe contact sensors is fitted with a screw clamp and is attached to pipes or rods using this.

Areas of application

Temperature sensors are used in a wide range of applications. In the industrial sector in particular, they are used to control processes such as ovens or to control the room temperature, for example in cold rooms. Here, the measured temperature value is transmitted from the sensor to a temperature controller which controls the system. Another area of application is the monitoring of machines to protect them from damage due to overheating. Likewise, in production processes, materials that should have a certain temperature are measured with a temperature sensor and the temperature is controlled accordingly. In injection moulding machines for moulding plastic parts, for example, the plastic granulate is heated to the appropriate setpoint in order to liquefy it and then pressed into the mould. In thermoforming, on the other hand, the material to be moulded is heated and drawn onto a mould using compressed air or a vacuum. Here too, the temperature of the moulding material is monitored using a temperature sensor.