What is a capacitive sphygmomanometer?
Capacitive barometer The electrical capacity of a capacitor is a function of the distance between the plates, their area and the dielectric ratio of the dielectric material, and is inversely related to the distance between the plates. In other words, as the distance between the plates decreases, its electrical capacity increases. The apparent resistance of capacitors, which are mostly used in AC circuits, is proportional to their electrical capacity. Therefore, the electrical capacitance of a capacitor can be calculated by measuring the apparent resistance of a capacitor in a Watson bridge circuit that is excited by ac voltage.
Capacitive measuring devices consist of a capacitive transducer. The pressure sensor, which can be a diaphragm, after receiving changes in fluid pressure, transfers it to one of the capacitor plates of the transducer and changes its capacity. As a result, by measuring the changes in the electrical capacitance of the capacitor, the pressure changes are calculated.
Capacitive barometer converter
These converters can be used in very large vacuums up to high pressures up to 10000PSI and therefore are widely used and with strain gauges, do not have much drift error. Usually the highest accuracy of these transducers is 1.0% and their lowest accuracy is 0.2%. Although this method is sensitive and accurate, but very dependent on temperature changes.
Advantages and Disadvantages
- Ability to withstand excessive loads compared to the diaphragm
- Measurement range 72 + bar to -1
- Operating temperature range 150 degrees to -40
- Vibration sensitive
- Lack of linear response
Rose Calibration Company in Melbourne, Australia with over ten years of experience provides all calibration, maintenance, and repair services throughout Australia. If you live in Sydney, Melbourne, Adelaide, Perth, Geelong, and Brisbane, you can receive your quote in less than two hours by fill-up the form via the “Booking” link.