Operation; Operating Controls; Putting The Device Into Operation; Heat-Up Phase Sequence - Herth+Buss SelectH2 Bedienhinweis

Operating Instruction
Safety notes
Even if a concentration under the LEL is
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measured in a certain position of the device
in the room, e.g. at normal working height,
it is possible that there may be a higher con-
centration in the explosive range in other
parts of the room or the building.
Gas testing method
The gas testing method with forming gas 5/95
(5% hydrogen in nitrogen) was developed to
locate the smallest leaks, those that cannot
be located using acoustic methods. The selec-
tion of hydrogen gas means there is no inter-
ference from other gases such as methane or
sludge gas. Please contact Herth+Buss for a
detailed description of the method, including
practical examples if required.
www.herthundbuss.com

2. Operation

2.1 Operating controls

Intake pipe
LED for different
measuring ranges
Display
Function buttons
Charging socket
Charge control
Exhaust gas outlet

2.2 Putting the device into operation

Before putting the device into operation,
make sure the built-in rechargeable bat-
tery is fully charged. Details can be found in
Chapter 5.
Press and hold the On/Off
button for approx. 2 sec-
onds. The device switches
on. All the available seg-
ments are shown briefly
on the display.
Then the gas type display (H2) and the word
HEAt appear on the display, announcing the
start of the 50-second heat-up cycle.
Operating Instruction

2.3 Heat-up phase sequence

The initialisation sequence is identical for
every start. As it progresses, the analogue
bar display expands towards the right
across the scale. Once the maximum value
has been reached, the device switches to
measuring mode.

2.3.1 Light-emitting diode chain displays

In the chain of light-emitting diodes - lo-
cated between the sensor head and the
switching buttons - the first diode shows
the "operation" .
If traces of gas are detected, this is shown
in the display and additional diodes are ac-
tivated depending on the concentration. The
acoustic signal (which can be deactivated)
means that the increase can also be heard.
When switching on, all the diodes light
up initially as a function check.
After the heat-up phase of approx.
45 seconds is completed, only the green
diode remains lit, indicating operational
readiness. 0 ppm becomes visible in the
display
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When a gas concentration arises and
increases, this is indicated in threshold
stages, from over 100 and 1000 ppm up
to 1 vol% (10000 ppm)
At the same time, the increase in gas
concentration is indicated by the change
in the acoustic signal.

2.4 Measuring operation

The time sequence of the heat-up phase is
tracked using the analogue bar that builds
up from the left to the right. After the heat-up
phase, the sensor zero point is determined
and applies as the fresh air reference value
for continued measuring operation.
All threshold LEDs are only active at the
start. The first roughly estimated measure-
ment value is available after approx. 12 sec-
onds and can only be displayed using the
threshold LEDs.
Once the heat-up phase is completed, the
device immediately switches to measuring
mode. Here, a low gas concentration under
999 is displayed in ppm and over 999 ppm
is displayed in vol%, starting with 0.1 vol%.
In the target gas-free atmosphere, the device
should display 0 ppm.
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