EX-5155
ENMET
5.2 Calibration of the EX-5155-MOS
Calibration is the process of setting the instrument up to read accurately when exposed to a target gas. The Zero function s
ets the
clean air reference point and the Span function sets the sensitivity of the instrument.
Initial Calibration: Wait 24 hours after initially supplying power to the
EX-5155-MOS sensor/transmitter (S/T) before initial
calibration. The S/T has been pre
-calibrated at the factory, and initial field calibration should result in only fine tuning to circuit,
as well as a way to che
ck that installation is successful. It is not necessary to open the enclosure to make adjustment. The
calibration functions are operated with magnets from outside the enclosure through the
MENU
and
SELECT
switches. Do Not open
the S/T unless the area is de
-classified.
Calibration Zero and Span functions are two separate procedures. They operate independently of each other. It is recommende
d
that the Zero procedure be done prior to the Span procedure.
ENMET
Corporation recommends at least quarterly calibration of
the EX-5155-MOS transmitters.
Calibration equipment is available from
ENMET
Corporation to calibrate the
EX-5155-MOS sensor/transmitters. A calibration
adapter will have a fitting for the gas cylinder on one side
, and a cover to go over the sensor housing on the other.
Generally, a cylinder of 20.9% Oxygen is used to provide a fresh air reference or Zero point for the calibration. Another cy
linder
is used to provide the Span reference point for calibration. De
pending on the instrument calibration, the Span gas may be the same
gas that the instrument is calibrated to display, or it may be another gas, which
ENMET
has found to have a similar response.
Sensors require a humidified calibration gas sample. Fill t
he humidifier bowl, half way up with clean fresh water prior to
attaching the Zero or Span gases. Be careful not to let the humidifier bowl tip, allowing water to enter the gas delivery tu
bing.
See
Table 3
for standard and Non-standard calibration gases.
Calibration Cover
Select
Input, for Calibration
or Optional Gas Sampling
Menu
Output, for Gas
Regulator
F
ROM
R
EGULATOR
&
G
AS CYLINDER
T
O
C
AL
C
OVER
Gas
Humidifier Top View
N
OTE
: Gas flow is opposite to arrow on humidifier
Figure 4: Calibration Adapter EX-5155-MOS Sensor/Transmitter
Manual Release Date –
November 26, 2018
Manual Part No. – 80003-098
P a g e
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