G - Physics – 01 – R
Patent
G - Physics
01
R
324/44
G01R 27/26 (2006.01) G01D 5/24 (2006.01) G01L 9/12 (2006.01)
Patent
CA 1262372
ABSTRACT OF THE DISCLOSURE A method for the measurement of capacitances, in par- ticular of low capacitances, utilizes measurement electronics which includes a measurement oscillator whose output frequency is a function of the capacitance to be connected to the input termi- nals of a circuit determining the frequency of such oscillator. In the method, two reference capacitances are used, whose elec- trical values are placed within the range of measurement and which are connected, being alternately exchanged with the capaci- tance or capacitances to be measured, to the measurement oscilla- tor while making use of a switching arrangement. Two external auxiliary references are used in the method. The auxiliary ref- erence signals obtained from the auxiliary references are com- pared with the corresponding output signals of the measurement electronics, derived from the reference capacitances. Signals representing the differences between the output signals and the signals coming from the external auxiliary references are formed. Feedback signals controlling the measurement electronics circuit are formed from the signals. The measurement electronics is con- trolled by the feedback signals in such a direction that the dif- ferential signals approach zero or a preset corresponding value. The output signal corresponding to the capacitance to be measured is determined by the measurement electronics adjusted correctly. The object is to provide a more precise method as well as such a two-reference measurement method and measurement circuit in which complicated computation operations are avoided. The output vari- ables corresponding to the reference detectors remain unchanged, even if the measurement electronics should creep. Such a circuit may be used in the telemetry of radiosondes in the measurement of atmospheric pressure, temperature and/or humidity.
482808
Marks & Clerk
Vaisala Oy
LandOfFree
Method for the measurement of capacitances, in particular of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the measurement of capacitances, in particular of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the measurement of capacitances, in particular of... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1244044