15
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 possi-
ble when no Memosens sensor is connected.
After power-on, a separate temperature probe is automatically recognized.
When you want to replace the temperature probe, you must switch off the meter
and then switch it on again.
Connections
a - Micro USB port
b - M8, 4 pins for Memosens sensors
c - Temperature probe GND
d - Temperature probe
e - pH socket (DIN 19 262)
Start-Up
NOTICE!
Always make sure that a sensor is connected to the meter before starting measure-
ment.
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, which allows convenient replacement
of sensors while the cable remains connected to the meter. The connecting cable is
connected to socket b (M8, 4 pins for Memosens sensors).
WARNING! Explosion Hazard
NEVER use digital Memosens sensors without Ex approval in a hazardous
location! For these applications, you must use Memosens sensors with Ex approval.
These sensors, as well as the hazardous-area cables, are marked by an orange-red
ring.
