Figure 4: cal of s, Co ral – ENMET SPECTRUM CO-RAL User Manual

Page 11

PECTRUM

CO RAL

ENMET Corporation

4.1.3

PECTRUM

CO RAL

Calibration

OTE

Calibration must be performed at normal room temperature (20-25°C) for optimal performance. If the instrument is

exposed to temperature extremes just prior to calibration, allow it to stabilize to room temperature. The internal
temperature of the instrument is verified by cycling through the "see DATA" menu.

In order to calibrate the instrument, it is first zeroed as previously described in Section 4.1.2. Then the sensor is presented with
a known concentration of the target gas, in air or an inert gas such as nitrogen, called the "span gas". After an appropriate
interval, which is timed, the new span setting is examined for validity.

A valid key entry sets the instrument at the "run ZERO" location of the maintenance menu. Press the

OPTION

pushbutton

once to access the "run CAL" display, then press the

SELECT

pushbutton; "AIR SET" is displayed. Zero the instrument as

described in Section 4.1.2. When the zero timer is complete, the display indicates "SPAN=XXX", where the numbers indicate
the correct span gas concentration for the instrument. The span gas value for this instrument is 20 ppm CO.

Assure that the correct span gas is available. Connect the calibration adapter to the cylinder, shown in Figure 4. Then press the

SELECT

button; "GAS SET" is displayed. Unplug the regulator-flowmeter assembly from the airline, connect it to the

calibration adapter. Then press the

SELECT

button; "XXX:0.Yv" is displayed. The XXX is a counter which counts down in

seconds to zero from 120 to provide the proper time interval for calibration. The 0.Yv indicates a sensor signal which is used
during the sensor replacement procedure. When the timer reaches zero, the new calibration and zero gas settings are examined
for validity. If the values are reasonable, the display is transferred to the gas concentration numerical display in the operations
menu. Return the regulator-flowmeter assembly to the airline.

If the new zero and calibration settings are not reasonable, "C-FAULT" is displayed. Turn the instrument OFF, then ON again.
This re-boots the system with the most recent valid zero and calibration settings.

ALARM

PPM CO

Figure 4: cal of S

PECTRUM

CO RAL

Pushbutton Switches

OWER

BACKLIGHT

PTION

ELECT

Quick Disconnect

Fittings

Gas Cylinder

Regulator