HY-ALERTA
TM
500 HANDHELD HYDROGEN LEAK
DETECTOR OPERATING MANUAL
90000002 R13
Page 9 of 14
4.2 HYDROGEN-FREE AREAS
For the purposes of this document a hydrogen-free area is one with less than 5ppm of hydrogen in the air.
It may be difficult to find a hydrogen-free area in a facility where hydrogen is used. Nearby rooms, or even the
entire building, may not be hydrogen free.
To check these areas reset or zero the sensor outside, away from any hydrogen tanks, pipes, or other
potential sources. Walk through the facility, watching the sensor. It is surprising how far low levels of
hydrogen can spread.
If the sensor is zeroed or reset in hydrogen, there will be a negative offset in the readings that could
compromise the sensor’s ability to find small leaks.
4.3 RESET OPERATION
The Reset operation is used to speed recovery from hydrogen exposure.
It can be invoked from the keypad while in the top menu level (measuring hydrogen) by pressing and holding
◄►(left and right arrow buttons simultaneously) or from the Reset Menu. Reset takes about 75 seconds to
complete.
WARNING:
THE INSTRUMENT MUST BE IN A HYDROGEN FREE ENVIRONMENT WITH THE LCD INDICATING LESS THAN
0.1% HYDROGEN BEFORE INVOKING THE RESET OPERATION.
4.4 ZERO OPERATION
The Zero Operation is used to zero the hydrogen reading if the instrument is reporting low levels (0.001% to
0.01%) of hydrogen when no hydrogen is present.
It can be invoked from the keypad while in the top menu level (measuring hydrogen) by pressing and holding
◄ (left arrow button) or from the Zero Menu. Zero takes about 10 seconds to complete.
WARNING:
THE INSTRUMENT MUST BE IN A HYDROGEN FREE ENVIRONMENT WITH THE LCD INDICATING LESS THAN
0.1% HYDROGEN BEFORE INVOKING THE ZERO OPERATION.
5
KEYPAD
5.1 NUMERICAL CHANGES
In the following sections when queried to change a numeric value the ▲ (up arrow) and ▼ (down arrow) keys
are used to increment/decrement the value based on the selected digit. If the ones digit is selected the value
will increment/decrement by one (1 increments to 2, 2 decrements to 1
). The ◄ (left arrow) and ► (right
arrow) keys are used to select another digit. To change a value of 0 to 100 first select the hundreds digit then
press the ▲ up arrow. Pressing ◄► (the left and right arrows simultaneously) will clear any changes made
and restore the previous value. Once the correct value is displayed press the
ENTER
key to save it.
5.2 TOP LEVEL KEYPAD FUNCTIONS
While in the hydrogen measurement screen, the keypad has these functions:
