PPM–400ST Formaldehyde Meter Operation Manual
drawn in. Wait for the value on the screen to reach a
peak and then start to drop.
3. Press and hold the
>
button – the display will show
the time taken for the value to reach it's peak in
seconds:
t 5.6
. Make a note of this time.
4. Press and hold the
<
button – the display will show
the peak value:
5.432
. Make a note of this peak value.
5. Turn the instrument off by holding down
the
%
button. Leave the instrument off for 5-minutes
before repeating the tests, attempting to calibrate or
taking another sample.
If the peak value recorded was less than
5.000
or the
time value recorded was less than
t 5.0
then there
may be a problem with the sampling system or the
sensor. Contact PPM Technology or your dealer for
further details.
Display Shows
ttp
Lo
after switching
ON
Known as 'Low Time To Peak', this is due to the
internal electrochemical fuel cell having dried out.
This problem can occur if the unit is being used to
sample in a very dry climate or environment. The fuel
cell will need to be hydrated to clear this message.
To hydrate the fuel cell, you will need to use a Sensor
Refresh Standard (available from PPM Technology or
your distributor).
The pump run time of the instrument will need to be
increased (10 to 20 seconds depending on instrument
and firmware version) by following the steps detailed
below:
1. Reset the instrument. This is detailed on the
following page.
2. Turn the instrument off. Once off, hold down both
<
and
>
buttons and the
$
button and switch the unit
on. If done correctly, you should see
OpEr
displayed
22
