wtw pH 171 2K, Operating Manual

Page: 102 / 160

Configuration
106
Selection of recorder output REC 1
(ST / 2K / R / RS models)
According to the set measuring dimension, the suitable recorder measuring ranges can be
selected.
Note: With overflow of the measuring range (OFL) the recorder outputs send a constant signal
of 20.5 mA. They automatically return to the set recorder measuring range after the
overflow is over.
Chart: Admissible recorder measuring ranges depending on the dimension:
Dimensions pH mV
REC ranges variable variable
Minimum
(Lower rating ) 0.00 to 10.00 pH -1000 ... +500 mV
Maximum
(Upper rating ) 4.00 to 14.00 pH -500 ... +1000 mV
Size of measuring range min. 4 pH units
max. 14 pH units min. 500 mV
max. 2000 mV
D/span
(Step size for setting) 1.00 100 mV
Ex-factory condition:
pH measuring range: 2 pH ... 12 pH corresponding to 4 ... 20 mA
Redox measuring range: -1000 mV ... +1000 mV corresponding to 4 ... 20 mA
Temp. measuring range (REC 2): 0
°°
C ... 50
°°
C corresponding to 4 ... 20 mA
Behaviour when being switched on
Operation mode after being switched on:
If - when being switched off (power failure) - the instrument was in an operation mode in which the
recorder actualization was interrupted the instrument will return to this operation mode after
being switched on again. This mode may be calibration as well as configuration of the
measuring mode.
If the instrument was in operation mode measured value - indication of reading mode before
being switched off it will return to this mode.
If the instrument was in none of above mentioned modes it will be in the "normal" measuring
mode.