Knick PORTAVO 904X PH, User Manual

Page: 14 / 68

14
Connecting a Sensor
The Portavo 904(X) PH provides several connections so that many types of sensors
can be used for measurement. Note that only
one
sensor may be connected to the
meter at a time.
The meter automatically recognizes a connected Memosens sensor and switches
accordingly. Memosens is signaled in the display.
Separate Temperature Probe
Note:
Temperature measurement using a separate temperature probe is only
possible when no Memosens sensor is connected.
After power-on, a separate temperature probe is automatically recognized. If you
want to replace the temperature probe, you must switch off the meter and then
switch it on again.
NOTICE!
Always make sure that a sensor is connected to the meter before starting
measurement.
Explanation: The analog pH input of the Portavo is an electrometer amplifier with
an extremely high-impedance. When the sensor is not in contact with the medium
or not connected to the meter, electric charges on the input can generate arbitrary,
stable pH or mV values, which will be shown in the display.
Memosens sensors have a
cable coupling
that allows for the convenient replace-
ment of sensors while the cable remains connected to the meter. The connecting
cable is connected to socket
b
(M8, 4 pins for Memosens sensors).
Commissioning
WARNING! Impairment of explosion protection.
Never use digital Memosens sensors or Memosens cables without Ex approval in a
hazardous location. For these applications, you must use Memosens sensors with
Ex approval. These sensors and the Memosens Ex cable are marked by an orange-red
ring.
a - Micro USB port
b - M8, 4 pins, for Memosens lab cable
c - Temperature probe GND
d - Temperature probe
e - pH socket in acc. with DIN 19 262 for
analog sensors
a b c d e