Other Types of Sensor

Hall sensors can be triggered by a ferrous float in the sight glass. We have not tried this technique so cannot vouch for its viability. You will have to experiment and see if this works. 

At an early stage of the project we tried using a reed switch/magnetic float device that looked very promising on paper, but when we tried the technique out, the laws of physics got in the way. We quickly found out how tenaciously magnets can cling to reed switches. 

Another possibility is acoustic/ultrasonic sensors. We have not experimented with these, so we do not have any information to offer in this regard. 

Most of these different types of sensors can be internally and/or externally positioned. Internal positioning of sensors requires more fabrication work and a customizing of the sight glass for probes and attendant components 

In general, level switches should be repeatable, reliable, and of a decent life cycle. The ambient conditions that the switch will have to operate in must 

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The interferometric sensor platform is highly sensitive and is the only one that provides an internal reference for compensation of refractive-index fluctuations and unspecific adsorption. Interferometric sensors have a broader dynamic range than most other types of sensors and show higher sensitivity as compared to other integrated optical biosensors . Due to the high sensitivity of the interferometer sensor the direct detection of small... 

Electrochemical hydrogen sensors are good down to 100 ppm, are hydrogen selective, have very low power consumption and are fairly resistant to poisoning. They operate within a narrow temperature range, require regular calibration, and usually have a shorter lifetime than other type of sensors. 

Other types of sensor tests, such as checking the vacuum-tight joints of the sensor, a vibration test, and so on, have usually been planned as one-factor experiments. 

The detectors used in gas chromatography for the detection of individual VOCs can also provide information about a mixture without a separation step. These VOC detectors include, for example, the flame-ionization detector (FID) and the photo-ionization detector (PID). Other direct-reading instruments have also been used for determining VOCs, such as photoacoustic spectroscopy (PAS) (see Chapter 1.6). Other types of sensors (e.g. electronic noses ) may become important in the future. 

Mass Sensitivity. Extreme sensitivity to changes in surface mass set AW devices apart from all other types of sensors. When mass is bound... 

The authors have seen many other types of sensors used in safety instrumented functions. These include ... 

Like any other type of sensor, the ideal photometric chemical sensor should not perturb the sample. In practice, this requires that the amount of analyte present to react with the indicator reagent should be small compared to the total amount of analyte in the sample. If this requirement is not met, then the contact of analyte with the reagent in the chemical transducer will result in a change in the analyte concentration in the sample. This, in turn, will result in a... 

A particular category of electrochemical sensors is the sensors able to detect the great variety of normal or pathologic parameters of living organisms. They can be designed either for analytical laboratory conditions, like any other type of sensor, or to be used in vivo, like implantable sensors. In the latter case, issues like their size. 

Other Types of Sensors Impedance-Based Sensors, FET Sensors, Acoustic Sensors... 

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