Temperature Sensors

Using a temperature sensor to monitor the temperature of equipment on a manufacturing site can prevent various problems caused by excessive loads or electric current, or by equipment malfunctions. It is also possible to activate cooling equipment with optimum timing.

Measuring temperature can prevent problems in the equipment caused by the influence of heat. For example, when a temperature sensor is set with the upper and lower limit temperatures to turn on/off the cooling equipment for the motor of a processing machine, the motor can be cooled with the appropriate timing when it gets hot due to excessive loads or other causes.

Since the temperature sensor can monitor the temperature continuously, the process in which the motor reaches a specified temperature and then is cooled can be understood. As a result, problems can be found and addressed at an early stage. For example, if the temperature of the motor does not change normally even though the processing machine is operating, the cooling equipment may not be operating properly or the motor may be overheated by an excessive load.

When a temperature sensor is used to measure the temperature around a target, it is possible to detect that the temperature has reached the upper or lower limit due to an abnormality with the air-conditioning system or to maintain optimum temperature control for the target. This allows for prevention of problems such as defective products produced due to abnormal temperatures.

Using a temperature sensor allows the prevention of problems such as those caused by abnormal rises or drops in the temperature during a coating process. When a temperature sensor is set with the upper and lower limit temperatures to turn on/off the air-conditioning system for the coating process, the line can be heated or cooled with the appropriate timing.

Since the temperature sensor can monitor the temperature continuously, the process of reaching a specified temperature can be understood. This allows for appropriate heating and cooling and accurate control of the time required for paint to dry. You can also find problems quickly, such as if the temperature does not change continuously even when the air-conditioning system is operating. This can help minimize the release of defective products.

Infrared temperature sensors can measure temperature from a distance with pin-point precision. You can prevent the production of defective products by measuring the temperature of minute parts during processing or detecting abnormal temperatures of tools and materials.

Using an infrared temperature sensor allows the prevention of problems such as those caused by low solder temperatures. When a temperature sensor is set with the temperature at which the activation of the solder heating equipment is required, heating can be started with the appropriate timing.

Infrared temperature sensors can measure temperature from a distance with pin-point precision. They can measure the temperature of minute sections, such as soldering of IC pins, without being affected by infrared radiation from the surrounding area of the processed section. Accumulating the data of continuous measurement of the temperature during soldering facilitates processing accuracy management, which was difficult with conventional methods, resulting in quality maintenance and improvement.

High-frequency induction heating is a processing method that uses a heating phenomenon called a skin or proximity effect. The process requires temperature measurement of workpieces heated by flames. Thermocouples and other contact-type temperature sensors cannot be used because they are damaged by high temperatures. With typical infrared temperature sensors, accurate measurement is impossible due to the influence of infrared energy emitted from the flames.

FT Series digital infrared temperature sensors are equipped with a newly developed circuit and center floating structure to maximize stability—the most important property of a temperature sensor. Despite its non-contact method, the FT Series can perform stable temperature measurement under various conditions. The FT Series also contributes to the automation of tasks that had been done by skilled workers based on personal experience, such as controlling residual heat that varies depending on the outside temperature.

The temperature of workpieces during hot forging rises to 900°C (1652°F) at maximum. Such temperature cannot be measured with contact-type temperature sensors. Even at locations more than 6 m (19.7') from workpieces, measurement errors occur because of the thermal expansion of sensors. This means that the temperatures of workpieces during hot forging must be measured from a distant location where the sensors will not be affected by the heat.

The FT Series digital infrared temperature sensor has no limit on its detecting distance. The lineup includes various models that can be selected according to the sizes of targets and the measurement ranges. Selecting an optimum model from the lineup allows for accurate measurement of the temperature of workpieces during hot forging from a distant location where the sensor will not be affected by the heat. These functions help to reduce the time and improve the accuracy of analyzing the relationship between temperature and shape of workpieces under high temperatures, which had been thought impossible with conventional sensors.

In this process, it takes some time for heated material to be poured into molds. This leads to variations in the temperature of the material, resulting in molding defects. Preventing such defects requires temperature control of the material immediately before pouring. In many cases, the space for installing a thermometer is limited and the operating environment is not clean, so there is also a need to address the dirt on the lens.

FT Series digital infrared temperature sensors have enclosed the detector, including the thermopile, in a cylindrical structure and made it float to avoid contact with the sensor head housing. The layer of air created by this floating structure can eliminate the influence of disturbances such as the ambient temperature of the sensors. The sensors also have compact bodies that can be installed anywhere. Since the detecting distance is unlimited, a location in a clean environment can be selected for installation.

The ratio of infrared rays emitted from objects (emissivity) differs depending on their materials and surface conditions, even if they have the same temperature. Consequently, accurate temperature measurement of an object requires setting of emissivity in accordance with the object.

The setting of emissivity varies depending on if you know the emissivity or not. With the FT Series, if you know the emissivity, you can just input the value on the amplifier unit. Even if you do not know the emissivity, you can set it automatically by just inputting the current temperature of the target on the amplifier unit. If you do not know the current temperature of the target, you can apply/affix the optional black body spray/tape onto the target and detect the surface temperature to set the emissivity.

Metal targets such as iron or aluminum have properties of high reflectance and low emissivity. The detection of targets with low emissivity may become unstable because the infrared temperature sensor will receive fewer infrared rays from the target. The emissivity of a glossy metal surface is low and it may decrease further when the surface is tilted. If the detection position changes, the temperature of the metal surface itself may change.

With the FT Series, stable detection is ensured when the sensor is mounted perpendicular to the target and it measures the same point every time. If there is any heat source such as people, operating equipment, or a heater, setting the emissivity in accordance with the target will enable accurate measurement.

Since infrared temperature sensors detect also visible steam or smoke, the measured temperature may include errors.

The FT Series uses an air purge function to remove steam or smoke between the sensor head and target, ensuring stable detection. If oil mist is floating in the air, you can reduce its influence by cleaning the lens surface of the sensor head regularly or enclosing the sensor head with a cylinder and using the air purge function to prevent the ingress of the oil. If the sensor head is heated by the radiant heat from the target and detection becomes inaccurate due to the high temperature of the thermopile inside, you can prevent the rise of the internal temperature by covering the sensor head with aluminum foil.