Caution; Effects Of Humidity; Effects Of Temperature - Ohio Medical Corporation MiniOX 1 Manual De Instrucciones

X 1
MiniO ® Oxygen Analyzer
If the instrument is calibrated to read 21% at 160 mmHg
partial pressure, then take the instrument to an area
above sea level, where the atmospheric pressure is 700
mmHg; a lower reading is found due to a lower partial
pressure.
PO = (21%) (700 mmHg)
2
PO
2
The percent reading on the instrument is derived by the
following formula:
PO Actual = X, 147 mmHg = X or,
2
PO Sea level 21% 167 mmHg 21%
2
(21%) (147 mmHg) = 19.3%
X =
(160 mmHg)
Therefore, to eliminate error caused by pressure
changes, the instrument must be calibrated at the
pressure it is to be used.
Do not expose the sensor to pressure
outside the range of 600 to 900 mmHg (23.62
to 35.43 inches Hg.) as this can produce
instrument errors.

Effects of Humidity

The presence of humidity in an oxygen sample
decreases the actual concentration of oxygen. Humidity
in a sample has the same effects as diluting the sample
with another gas.
For example:
If 100% oxygen is saturated with 100% humidity,
the actual concentration of oxygen drops from
100% to 96-97%. The instrument indicates this
drop in concentration.
4-3
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= 147 mmHg

CAUTION

P/N 711462 (Rev.3) 02/2016
If moisture condenses on the diffusion membrane of
the sensor face, the oxygen path is physically blocked
and a lower oxygen concentration is indicated. This is
typical of all oxygen gas sensors, and is more likely to
occur when the sensor is located downstream from a
humidifier.
Mount the sensor, when used in a breathing circuit, so
the deflector points downward to prevent moisture from
draining onto the diffusion membrane (see Figure 4-1).
Also, mount the sensor, when possible, upstream of the
humidifier.

Effects of Temperature

Each MiniOX 1 sensor is desensitized to temperature
®
changes using a thermistor (temperature variable
resistor) located within the sensor. Variations in the
sensor reading due to temperature changes, are less
than 3% when used or calibrated between 0 to 40
degrees centigrade. By using the instrument close to the
temperature at which it is calibrated, variations can be
minimized.
Operating Temperature Range:
0 to 40 C (32
o o
Do not use instrument outside operating
temperature range.
Do not handle the sensor more than
necessary during calibration or use. Body
heat can cause the sensor's thermistor to
change disproportional to the change in gas
sample temperature at the sensing electrode.
This can produce some error, until thermal
equilibrium is restored.
Section 4, Operation
to 104 F)
o o
CAUTION
CAUTION