ENMET SPECTRUM SP User Manual

Page 10

SPECTRUM SP Series

ENMET Corporation

3.1.1 Key

Entrance to the maintenance menu is guarded with a four digit numerical key. The factory default setting of the key is 1270*.
When the valid numerical key is inserted, the user is allowed to enter the maintenance menu

When in the "go SETUP" location, press the

SELECT

pushbutton; "Key=0000" is displayed. The underscore cursor is under

the left hand digit. To insert the key, press the

OPTION

pushbutton to change the left hand digit, and choose the correct digit;

then press the

SELECT

pushbutton, which locks in the chosen left hand digit and moves the underscore cursor one space to the

right. Continue this process until the four digit key is complete. When the valid key is inserted in this manner, the display is
transferred to the "run ZERO" portion of the maintenance menu. When an invalid key is inserted, "INVALID" is briefly
displayed, and the instrument returns to the operational display.

*The process by which a different key is set is given in section 3.1.5.

3.1.2 Zero

A valid key entry sets the instrument at the "run ZERO" location, of the maintenance menu, which enables the setting of the
zero gas concentration point. This is desirable if the zero reference of the gas sensor has drifted over a period of time, indicated
by a persistent gas concentration reading in a clean environment. Note that the calibration sequence given below also includes
setting the zero point. If a full calibration is required, instead of setting just the zero point, push the

OPTION

button once; "run

CAL" is displayed. See section 3.1.3.

To set the zero point without performing full calibration, from the "run ZERO" location press the

SELECT

pushbutton; "AIR

SET?" is displayed. Be certain that the instrument is in clean air, uncontaminated by the target gas. If uncertain of the
environment, use pure compressed air from a pressurized cylinder, and flow it over the sensor at a low rate.

With the instrument in “AIR SET?”, press the

SELECT

pushbutton again. "z30:0.0v" is displayed; this is a counter that counts

down in seconds from 30 to 0. The validity of the new zero setting is then examined; if it is with in preset parameters, the
display is transferred to the operational display in the operation menu.

If the new zero setting is not between preset parameters, "C-FAULT" is displayed. Turn the instrument OFF, then ON again.
This re-boots the system with the most recent valid zero setting.

3.1.3 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 in a procedure similar to the one described section 3.1.2. 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 paragraph 3.1.2. When the zero timer is complete, the display indicates "GAS=XXXX", where the numbers
indicate the correct span gas concentration the instrument is equipped to detect; for a

SPECTRUM SP

the span gas is 100

ppm CO, for Cl2

SPECTRUM SP

the span gas is 5 ppm chlorine, and so forth. The correct span gas is given in Table 2

Appendix A for various target gases.

At the “GAS=XXXX” display:

Assure that the correct span gas is available.

Connect the calibration adapter to the cylinder.

Connect the quick release fitting to the sensor input.

Press the

SELECT

pushbutton; "GAS SET?" is displayed.

Press the

SELECT

pushbutton; "XXX:Y.Yv" is displayed until countdown is complete.

Remove span gas.

The XXX is a counter that counts down in seconds to zero from the correct starting time to provide the proper time interval for
calibration; this time interval may vary depending on your target gas. The Y.Y v indicates a sensor signal that 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 value is within preset parameters, the display is transferred to the gas operational display in the operations menu.

OTE

After calibration the audio alarm is disabled up to 2.5 minutes.

If the new setting is not within preset parameters, "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. Recalibrate. If after recalibration the instrument still
displays “C-FAULT” the sensor may be expired. Replace sensor in accordance with Section 3.2.1.