Technical data

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A fault of the transmitters is indicated by the constantly lit yellow fault LED, the current interface
provides 1.2 mA an error message is shown in the display (SYS ERR. or SENS ERR.).
Fault report is given, if:
• the sensor or the circuitry in the transmitter is defective;
• the sensor is missing;
• the self-test of the unit recognizes a failure.
For further causes see „Special Status and relevant Error Messages“ on page 21.
After the fault is cured, the yellow fault LED expires.
Check and AutoCal Adjustment of Zeropoint (ZERO)
A prerequisite for this check is atmospheric air without disturbing, resp. interfering gas components.
In polluted atmospheres you may alternatively use zero gas, which is free from combustible
components and interfering matters. Supply the zero gas to the sensor without pressure by means of
the flow adapter, at a flow rate of approx. 0.5 l/min.
Once the type of gas has been changed or the sensor has been replaced, the zeropoint must be
adjusted correctly. If the detection mode shows a deviation from 0 the zeropoint has to be corrected
as well. When the reading is constant the adjustment can be done using the AutoCal feature. The
AutoCal program automatically adjusts the zeropoint signal.
Conditions
The automatic zeropoint adjustment by means of the AutoZero key or with the standard access code
0011 is only possible, if the currently displayed value is max. 25 % LEL.
Expert users have the possibility to activate the zeropoint adjustment even for a display of 35 % LEL
by entering the access code 0055. This access code should only be used by trained safety personnel
of the customer.
Should the current zeropoint indication be higher than a value of 35 % LEL but it is for sure that this
value is not gas induced, the sub-menu info of the service menu indicates a temporarily valid (max.
1 hour) code (Code), which allows the activation of the zeropoint adjustment without any limitations.
Note:
If the last mentioned measure becomes necessary, this might be caused by a faulty sensor, which
should be replaced as soon as possible.
Execution
When the user presses the AutoZero key at a transmitter without display he cannot see whether the
measurement value is within the allowed tolerance band for zeroing (i.e. < 25 % LEL). Should the
measurement value be higher than 25 % LEL when the AutoZero key is pressed, the transmitter
remains in detection mode – to be identified by the fact that the fault LED is not lit. In this case the
zeropoint adjustment is only possible by means of the remote control.
For quick adjustment by means of the secured AutoZero key at the left side of the casing remove the
lock screw and press the key for at least 3 seconds. This switches the current output to 2.0 mA, the
fault LED flashes slowly, and step 3 below is started automatically.
When using the keypad at the display or at the remote control, follow the order below:
1. Press key
ZERO
TEST
for at least 3 seconds to activate the program.
During the whole procedure the current interface provides 2.02 mA and the fault LED
flashes slowly.
The display shortly reads CodE.
2. Enter the numeric access code 0011 (resp.
0055). Use keys
ZERO
TEST
and
SPAN
INFO
to change the
figure at the current position, then confirm by means of key
QUIT
MENU
.