Testing The Sensor Via A Transmitter - Mettler Toledo InPro6900 Bedienungsanleitung

22
If the LED does not light up, you should check the
battery of the O
manual «Accessories» ). If the battery is working,
than there is probably a problem with your sensor.
You should change the electrolyte and/or the
membrane body of your sensor. If after a
membrane change the LED still does not light up,
this means that there is maybe something wrong
with the interior body of the sensor. You should
than change it (see «Section 6.2»).
Important! The Sensor Check function only verifies
the correctness of the electrode current for air
measurement. In order to be absolutely sure of the
functionality of the sensor, the residual signal in an
oxygen free medium should also be controlled (see
«Section 6.1.3»).

6.1.3 Testing the sensor via a transmitter

A periodic zero current measurement (no zero point
calibration) is recommended for verification of proper
sensor function.
Note: At the time you carry out the zero current
measurement, the sensor must be polarized.
Zero current measurement can be done by using
zero ing gel (order no. 34 100 1032) or nitrogen (N
or carbon dioxide (CO
of at least 99.995 %, alternatively in a sample medium
saturated with one of these gases.
After 2 minutes in an oxygen-free sample medium, the
reading on the transmitter should drop to below 10%
of the reading in ambient air, and within 10 minutes
the value should have dropped to below 1 %.
If the measured values are too high, this suggests a
depleted electrolyte or a defective membrane. In the
first instance replace the electrolyte, and in the second
case exchange both the membrane body and the elec-
trolyte accordingly.
If after such procedures the above mentioned values
are still not reached, replace the interior body. If this
doesn't solve the problem too send the sensor to your
local METTLER TOLEDO representative for inspection.
Many sample media contain volatile substances
which, even at very low concentrations, have a clearly
perceptible smell. Similarly to oxygen, these
substances are able to invade the electrolyte through
the gas-permeable membrane. Accordingly, they
become noticeable when changing the electrolyte. In
most cases, such substances have absolutely no
influence on the measuring properties of the sensor.
Slight discoloration of the electrolyte also has no effect
on the measuring properties.
InPro 6900
52 201 029
InPro 6900 Series O
Sensor-Master (see instruction
2
) calibration gases with a purity
2
© 12 / 15 Mettler-Toledo GmbH
Sensor 12 mm
2
Printed in Switzerland
)
2