ENMET SPECTRUM CO-RAL User Manual

Page 10

ENMET Corporation

PECTRUM

CO RAL

4.1.1 Entering 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 4.1.6.

4.1.2 Setting Zero Point

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 4.1.3.

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 clean 20.9% by volume oxygen compressed air from a pressurized cylinder. See Section 5.0 for

ENMET

part

number.

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.