A digital anemometer

Author

Okamoto, Ken ; Ohhashi, Tadahiko ; Asakura, Masahiro ; Watanabe, Kenzo

Author_Institution

Dev. Lab., Kurabe Ind. Corp., Hamamatsu, Japan

Volume

43

Issue

2

fYear

1994

fDate

4/1/1994 12:00:00 AM

Firstpage

116

Lastpage

120

Abstract

A digital anemometer has been developed for air flow measurements in home and office environments. The principle is based on hot-wire anemometry. The probe consists of a cold thermistor for flow temperature detection and a hot thermistor for flow rate detection. The latter is self-heated by a thermal bridge. Its unbalance voltage due to the air flow is compared with the reference response transformed into the time domain by direct digital synthesizing. This pulse-width modulation provides the linear digital representation of the flow rate under measurement. The unbalance component due to flow temperature is compensated by scaling the reference response depending on temperature detected by a cold thermistor. These linearization and compensation techniques make accurate measurements possible with a simple configuration. Performances of a prototype anemometer built using a one-chip 4-bit microcomputer are also presented to demonstrate the validity of these techniques

Keywords

anemometers; bridge circuits; bridge instruments; compensation; computerised instrumentation; digital instrumentation; flow measurement; linearisation techniques; microcomputer applications; pulse width modulation; temperature measurement; thermistors; air conditioning; air flow measurement; cold thermistor; digital anemometer; direct digital synthesizing; flow rate detection; flow temperature; flow temperature detection; home; hot thermistor; hot-wire anemometry; linear digital representation; office environment; one-chip 4-bit microcomputer; pulse-width modulation; reference response; self-heating; thermal bridge; unbalance voltage;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.293406

Filename

293406