Housing temperature sensors

A thermopile sensor generates an output voltage that depends on the temperature difference between its hot and cold contacts. For infrared temperature measurement, the hot contacts are normally thermally insulated and placed on a thin membrane, whereas the cold contacts are thermally connected to the metal housing. Infrared radiation, which is absorbed by the hot contacts of the thermopile, causes a temperature difference between hot and cold contacts. The resulting output voltage is a measure for the temperature difference between radiation source and cold contacts of the thermopile sensor. It is therefore necessary to measure also the temperature of the cold contacts by an additional ambient temperature sensor in order to determine the temperature of the radiation source. 

In order to use the sensor on an industrial scale, an appropriate housing is needed in which the required electrodes and temperature sensor are positioned in the scientifically and technically most considered and logical way. Additional requirements imply that the system should be robust and offer good protection against blows and/or other possible causes of defects. The system should be easy to handle, electrodes and other components should be straightforward to replace, the calibration of the electrodes should be accomplishable in a quick and particularly simple way, and the system must... 

Fig. 3. Schematic design of temperature sensors. One or more thermoresistors are packed into a stainless steel housing. 3- or 4-strand cabling is recommended...

Fig. 35. Schematic diagram of the rotating-cylinder reactor. 1, thermometer 2, temperature controller 3, housing 4, reactor inlet bolt 5, stirrer 6, temperature sensor 7, bearing 8, temperature sensor wire leads 9, stirrer shaft belt 10, stirrer motor 11, reactor holder 12, reaction chamber 13, water jacket inlet 14, O-ring 15, volume sensor 16, volume sensor wire leads 17, rotating chamber belt 18, rotating chamber motor 19, base place 20, reactor outlet bolt 21, water jacket outlet. (Reprinted with permission from Chem. Eng. Sci. 43,2025, J. H. Kim, E. D. Sudol, M. S. El-Aasser, J. W. Vanderhoff, Copyright 1988, Pergamon Press pic.)...

Some units have a temperature sensor attached by soft glue to one of the internal batteries for temperature compensation during charging. When you change batteries, carefully peel the sensor off the old battery and apply to the new battery. If the sensor needs to be replaced, most electronic supply houses carry them. 

The meteorological sensors are mounted at the top of a 7 m tower, located in a clearing 40 m south of Spruce Tree House. The sensors are thus about 5 m above the elevation of the test walls, and just above the forest canopy within the canyon. The exposure of the instruments was chosen to reflect accurately the specific environment experienced by the test walls and Spruce Tree House. The non-intensive experiments are located in the same clearing, on a separate mast about 2.5 m tall. In addition, temperature transducers and surface time-of-wetness sensors have been mounted on the test walls. These parameters are also recorded on digital tape. 

The classic sensor consists of a housing, connector, NTC, heat-conducting material, and gasket. So far there is no standard in the automotive industry for temperature sensors. In the market we find an endless variety of threads, NTC curves, connectors or cable exit with connector, gasket materials, and housing materials. There are certain trends though (Tab. 7.5.2). In a market survey 35 temperature sensors used by European manufacturers for underhood applications... 

The key element in the wheel electronics is the sensor. Specially developed components for this application nowadays combine the pressure sensor, a temperature sensor, and the complete signal processing and data interface in the same hous-... 

Another research group has created an electrochemical microdevice which supports both amplification and detection of DNA". The integrated chip houses an 8 pL reaction chamber, the associated temperature sensors and heaters and two electrochemical detection techniques, including metal complex intercalators and nanogold particles. The sensitivity of the device allows the detection of a few hundred copies of target DNA. 

Figure 15.12 A commercial ISFET pH probe, with a silicon chip pH sensor, a built in reference electrode, and a built-in temperature sensor. This pH probe is housed in a stainless steel body with a slanted tip for easy insertion into meat or other soft solid samples. (Courtesy of IQ Scientific Instmments, Inc. San Diego, CA.)...

Currently plastics represent around 13% of the total weight of a medium-sized car and industry experts believe that 90% of future car design improvements and innovations will have an electronic content such as electronic tyre pressure monitors installed to improved road safety. The ultimate tyre pressure monitor has been fitted to the world s fastest road car, the Bugatti Veyron 16.4. Its wheel electronics comprise a military grade battery, absolute pressure sensor, temperature sensor, accelerometer micro-controller and radio transmitter/receiver which are housed in a compact wheel housing made from PEEK. 

The setup is largely comprised of a continuous-flow, compensating calorimeter which consists of a flooded measuring kettle housed in an intermediate thermostat, which is enveloped by a base thermostat. The base thermostat and the intermediate thermostat are filled with a thermostat liquid. The base thermostat, the intermediate thermostat and the flow measuring kettle are each provided with a mixer, baffles and temperature sensors. The mixer of the base and intermediate thermostats are classic stirrers, and the mixer in the flooded measuring kettle is a circular pendulum mixer. Its bearing is protected from contamination with the reaction mixture by corrugated metal bellows, which is joined to the cover of the shaft to form a seal. 

Intelligent transmitters have two major components (1) a sensor module which comprises the process connections and sensor assembly, and (2) a two-compartment electronics housing with a terminal block and an electronics module that contains signal conditioning circuits and a microprocessor. Figure 6.9 illustrates how the primary output signal is compensated for errors caused in pressure-sensor temperature. An internal sensor measures the temperature of the pressure sensor. This measurement is fed into the microprocessor where the primary measurement signal is appropriately corrected. This temperature measurement is also transmitted to receivers over the communications network. 

The sensor unit of an IRET usually consists of an infrared sensor, in most cases a thermopile sensor in a TO-5 or TO-46 housing, a gold plated barrel, which reflects the infrared radiation from the ear to the sensor and reduces the sensitivity of the sensor to ambient temperature changes (see Fig. 3.43). 

---