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Idiomas disponibles
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Maintenance
9
Maintenance
– The maintenance intervals must be established for each
individual installation. Depending on safety considerations
and application specific conditions the instrument is used
in, these might need to be shortened.
Every 12 months
– Inspection by trained service personnel.
– Check signal transmission to the control unit, LEDs and
triggering of alarm devices.
– Perform bump test
9.1
Sensor replacement
A sensor can be replaced in the hazardous, classified area,
without interrupting the power supply.
Sensor change function
With the menu function Change Sensor, a sensor can be
changed during operation without triggering a fault signal at
the control unit. It also ensures that all sensor data in the
microprocessor can be saved in the sensor memory
(EEPROM) before disconnecting the sensor.
Replacing the sensor
Refer to figure B on the fold-out page.
A sensor can be replaced at any time.
1. Select Settings > Sensor > Change Sensor and confirm.
The maintenance signal is generated on the 4-20mA
interface. The display shows Please remove the
sensor.
The Maintenance symbol is displayed.
2. Replace the old sensor with a new sensor:
a. Loosen set-screw (2)
b. Unscrew bayonet ring (3)
c. Remove old sensor.
d. Insert sensor (4) into the opening. The Dräger logo on
the sensor must point to the mark on the sensing head
housing (5).
e. Lock sensor with bayonet ring (3)
f. Tighten set-screw (2).
The display shows: Loading data, please wait
3. When the sensor data are loaded, the display shows: Data
loaded.
4. Select Back to menu and confirm.
The maintenance signal on the 4-20mA interface
remains pending until the sensor is warmed-up.
5. Perform bump test to check the instrument for proper
operation.
6. Check the installation requirements and instrument for SIL
status.
18
10
Instrument settings
10.1 Alarms and delay
To avoid false alarms triggered by short ultrasonic peaks,
do not use alarm settings of the instrument without alarm
delay.
10.1.1 Changing unit
The displayed unit can be changed to the relative unit % of
the measuring range.
1. Select Settings > Sensor > Gas settings > UGLD > %
and confirm with OK.
Range /% 100.00 is displayed.
Do not change this range!
2. Select Next and confirm with Confirm.
✓ The unit is changed.
10.1.2 Switching the alarms on or off
If the alarm is set to Off, an alarm condition will not be shown
by the LEDs or asserted relays! Using relays the maintenance
signal is transmitted via the 4-20 mA interface and the symbol
is displayed.
1. Select Settings > Instrument > Alarm > Alarm on/off.
2. Select Enable or Disable and confirm.
10.1.3 Configuring alarms
1. Select Settings > Instrument > Alarm > Alarm A1 or
Alarm A2 and confirm.
The current alarm threshold is displayed.
2. Apply settings and confirm the configuration steps
successively with Next.
a. Set value for alarm threshold.
b. Set alarm direction.
Rising
Falling
c. Set latching mode.
Latching
Non-latching
d. Set acknowledgement mode.
Instructions for use
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Dräger Polytron
The alarm direction is called rising, if the
gas concentration has to exceed a certain
value to activate an alarm.
The alarm direction is called falling, if the
gas concentration has to fall below a certain
value to activate an alarm.
Once the alarm threshold is reached, the
instrument will trigger the alarm. It will
remain in alarm status even if the gas con-
centration does not meet the alarm condi-
tion any more. To clear a latching alarm it
has to be acknowledged.
The alarm status clears if the gas concen-
tration does not meet the alarm condition
anymore.
®
8900 UGLD Firmware version ≥ 4.0.x
