37
(8)
: The hold mode is never enabled by the control timing
if the “hold time start” is the same as the “hold time end” .
Items “C .41” and “C .42” apply to all days . The hold mode
can be enabled all day by using items “C .51” through
“C .57” .
(9)
: See the “Temperature compensation” subsection for
more details on how the Automatic temperature compensa-
tion and Manual temperature compensation work .
(10)
: Whenever the pH/ORP selection item is changed from
pH into ORP or vice versa all of the calibration and setup
data regarding pH (when changing to ORP) or ORP (when
changing to pH) are kept . They are automatically restored
if the controlled parameter is changed back later . The fol-
lowing setup items cannot vary when changing from pH to
ORP or vice versa (because they are items strictly related
to the instrument and not to the controlled magnitude):
Factory ID, Process ID alias RS485 address, Calibration/
hold password, General password, Baud rate, Modem calls
answer enable, Cellular/PC connection items, Hardware
identifier and RTC date and time . For proper operation
while working with the Digital Transmitter, this item must be
equal to the correspondent one in the Digital Transmitter . If
the two values do not coincide a “Digital Transmitter error”
is generated .
(11)
: A life check error is generated if the pH reading does
not vary for more than ±0 .10 pH within the time selected
through the “life check time” item (pH controller) or mV
reading for more than ±10 mV within the same time (ORP
controller) .
(12)
: When the Digital transmitter (
HI504910
) is used, the
temperature is measured by the transmitter along with pH
(pH controller), or ORP (ORP controller) . These measure-
ments are sent to the Process Controller . The calibration data
set for the Digital Transmitter is kept within the transmitter
and thus it is separated from the BNC set . This means that
the calibration slope and offset and the other GLP data
are automatically switched from the BNC set to the Digital
Transmitter set and vice versa when the measurement input
is switched from “Prob” to “trAn” respectively . For example,
if the user was using a pH electrode connected to the BNC,
and at a later time he starts using the transmitter, and after
that the measurement input selection is reverted back to
“Prob”, it is not necessary to calibrate the pH electrode
again .
