EP 1977228 A1 20081008 - MEASURING DEVICE FOR MEASURING THE OXYGEN FRACTION IN RESPIRATORY AIR
Title (en)
MEASURING DEVICE FOR MEASURING THE OXYGEN FRACTION IN RESPIRATORY AIR
Title (de)
MESSGERAT ZUM MESSEN DES SAUERSTOFFANTEILS IN DER ATEMLUFT
Title (fr)
INSTRUMENT DE MESURE MESURANT LA TENEUR EN OXYGÈNE DANS L'AIR RESPIRABLE
Publication
Application
Priority
- EP 2006011922 W 20061212
- DE 102006004051 A 20060128
Abstract (en)
[origin: WO2007085288A1] The invention relates to a measuring device for measuring the oxygen fraction in respiratory air, in particular for the supply of respiratory air in aircraft. Said device has an oxygen sensor (10), to which an electric, analogue, sinusoidal input signal with a fixed base frequency (1f) is fed and which emits an electric analogue output signal containing a useful signal component with a double base frequency (2f) and at least one interference signal component with a base frequency (1f), in addition to an evaluation circuit (26) for determining a measured value as a measurement of the oxygen fraction, the output signal being fed to said circuit. To improve the measuring accuracy of the measuring device, whilst simultaneously reducing fluctuations in the measured values, an adder (14) is located between the oxygen sensor (10) and the evaluation circuit (26). Both the output signal and a sinusoidal reference signal with a base frequency (1f) are fed to said adder. The phase and amplitude of the reference signal are set in such a way that the interference signal component(s) is or are compensated to a great extent in the output signal of the adder (14).
IPC 8 full level
G01N 27/76 (2006.01); G01N 33/497 (2006.01)
CPC (source: EP US)
G01N 33/497 (2013.01 - EP US)
Citation (search report)
See references of WO 2007085288A1
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR
DOCDB simple family (publication)
WO 2007085288 A1 20070802; DE 102006004051 A1 20070809; EP 1977228 A1 20081008; US 2009007633 A1 20090108
DOCDB simple family (application)
EP 2006011922 W 20061212; DE 102006004051 A 20060128; EP 06829509 A 20061212; US 8773506 A 20061212