Thermo Fisher Scientific Alpha pH 100 - Manual (Page 20)

19
6. Using the Controller Current Loop for
Datalogging (for Transmitter Model Only)
The 4-20 mA Current Loop
A 4-20 mA current loop can be connected if a remote data
logging is required. The current will be proportional to the
pH/ORP displayed on the panel display. The 4-20 mA current
loop can drive a load resistance of no more than 200
Ω .
If the pH is less than 0.0 pH, the current signal will be set to
approximately 0 mA. If the pH is greater than 14.0 pH, it will be
set to approximately 21 mA. In this way, the remote data logger
can detect when out of range conditions arise. Please note that
the 4-20 mA loop is not galvanically isolated from the source.