US 6,279,377 B1 · Method and apparatus for monitoring oxygen concentration

Abstract

Apparatus for measuring concentration of oxygen includes a plurality of status displays, identifying concentration status relative to a plurality of thresholds, an alarm for immediate and prominent identification of status relative to a threshold of particular significance, and a quantitative display indicative of an actual concentration. Although measurements are performed and results are indicated relative to a number of thresholds, only a single calibration procedure is required, using only a single calibration gas. The apparatus is calibrated by adjusting a circuit parameter of one of the circuit components to vary a sensed output value to correspond to a narrow range surrounding the known concentration of the calibration gas. Both the circuit parameter and the actually sensed output value are stored. In a monitoring operation, the circuit parameter is retrieved to reset the circuit component to its calibrated setting. The monitored unknown value of concentration is scaled based on a value in a look-up table and on the actually sensed output value of the calibration process. An interpolation between values of the look-up table is then used to identify a concentration corresponding to the scaled value.

Claims18

Dependent claims

An oxygen monitor comprising:

a sensor for sensing oxygen concentration by providing output values indicative thereof;
a status display representing a value of sensed oxygen concentration relative to a plurality of threshold values,
said monitor further comprising a control processor for generating status displays for a plurality of threshold values in accordance with calibration by a single calibration gas, wherein said monitor comprises a component varying an output of said sensor, and said control processor comprises:
calibrating means for calibrating said sensor by varying an operating parameter of said component of said monitor to a calibration value providing an output value of said sensor corresponding to a concentration of said calibration gas;
storage means for storing said calibration value of said component;
and
retrieving means operable during a monitoring operation for retrieving said calibration value from said storage means and for setting said operating parameter of said component to said calibration value to perform the monitoring operation.

4 more elements

A method for monitoring oxygen concentration comprising the steps of:

calibrating a sensor using a single calibration gas;
sensing an unknown oxygen concentration and providing output values indicative thereof;
generating status displays relative to a plurality of threshold values in accordance with said calibration by said single calibration gas;
displaying concentration of the oxygen being monitored for a plurality of ranges in accordance with said calibration by said single calibration gas;
wherein said calibrating step comprises varying an operating parameter of a component varying an output of said sensor to obtain a calibration value corresponding to a concentration of said calibration gas;
storing said calibration value of said component;
and
during a monitoring operation, retrieving said calibration value for setting said operating parameter of said component to said calibration value to perform the monitoring operation.

5 more elements

A gas concentration monitor comprising:

a sensor for sensing concentration of a gas and providing output values indicative of the concentration;
a status display which provides an indication of a relationship between a value of the sensed gas concentration and a plurality of threshold values;
a control processor for generating signals to drive said status display for indicating said relationship to said plurality of threshold values in response to a calibration by a single calibration gas;
and
a concentration display for displaying the concentration of the gas being monitored, said control processor controlling said concentration display to display said concentration in accordance with said calibration by a single calibration gas.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for monitoring oxygen concentration

Life of this patent

Method and apparatus for monitoring oxygen concentration

Life of this patent

Abstract

Claims18