1 Introduction
Theory of Operation
12
INOP Alarms
INOP alarms are triggered if:
• The gas analyzer is disconnected or switched off.
• The gas analyzer accuracy is in doubt.
• The equipment or any of its components malfunctions.
• Zero calibration has failed.
• The gas sample tube is occluded, or the watertrap is full.
• Any parameter is unable to measure.
• Any parameter is out of range.
• The gas analyzer is in warm-up mode.
• Gas analyzer calibration is running.
• Gas analyzer alarms are suppressed.
• No breath detected.
Theory of Operation
General Measurement Principles
The M1013A IntelliVue G1 and the M1019A IntelliVue G5 use infrared technology to measure the
concentration of the gases CO
2
, N
2
O and the volatile anesthetic agents.
The gases which can be measured by the gas analyzer absorb infrared (IR) light. Each gas has its own
absorption characteristic. The gas is transported into a sample cell, and an optical IR filter selects a
specific band of IR light which has passed through the gas. For multiple gas measurement, such as in
the IntelliVue G1 and G5, there are multiple IR filters. The higher the concentration of gas in a given
volume the more IR light is absorbed. This means that higher concentrations of IR absorbing gas cause
a lower transmission of IR light. The amount of IR light transmitted after it has been passed through
the gas is measured. From the amount of IR light measured, the concentration of gas present can be
calculated. This calculation provides the gas measurement value. Oxygen is measured using a
paramagnetic cell.
N O T E
The presence of organic cleaning solutions or gases containing freon may impact the accuracy of the
infrared gas measurement.
O
2
Sensor
N O T E
The O
2
Sensor is optional with IntelliVue G1 and standard with IntelliVue G5
Measurement Principle
The O
2
sensor uses a fast O
2
measurement technique that utilizes the paramagnetic properties of
oxygen.
