Specifications

MI 611-211 – October 2005 3. Operation
22
INSTRMNT STAB IND
When performing a calibration, the transmitter checks for stability in absolute measurement and
temperature before accepting a change. This section enables you to configure the
TIME allowed to
attain stability and the amount of fluctuation (VAR) allowed. The value of VAR corresponds to
the least significant digit of the measurement in the
PRIMARY DISPLAY you configured in
“Config Display” on page 17. For example, if you configured the
PRIMARY RESOLUTION as
0.01 pH, then the value of VAR would be from 0.01 to 0.09 pH expressed as from 1 to 9. Both
TIME and VAR are configured individually in STAB IND MEASurement and
STAB IND TEMPerature.
First, configure
STAB IND MEAS as ON or OFF. If you configure this as ON, you need to specify
the
TIME between 5 and 60 seconds (in 5-second increments) and the VARiable between 1 and 9.
A longer time period and a smaller measurement value assures more stability during calibration.
The default
TIME is 5 seconds and the default VARiable is 9. Thus, if the primary resolution was
0.01 and the default time and variable are used, the values can change at a rate of 0.09 pH over 5
seconds.
Then repeat the procedure for
STAB IND TEMP. If you configure this as ON, you need to specify
the TIME between 5 and 60 seconds (in 5-second increments) and the VARiable between 1 and 9
(°C or °F). The default TIME is 5 seconds and the default VARiable is 9.
Config Timeout
(Refer to “Structure Diagram 4” on page 41.)
This section of the structure asks you to specify the time in which the instrument will bring you
back to the on-line/Measurement mode from another on-line mode (Status, Diagnostics, or the
view only part of Configuration) when no keyboard input has occurred. In Measure mode,
TIMEOUT also limits the time to view a secondary display other than that configured in CONFIG
DISPLAY
. The time may be specified between 0 and 999 seconds. A value of zero (0) disables the
time-out function. The default time is 600 (10 minutes).
Config Buffers
(Refer to “Structure Diagram 5” on page 42.)
NOTE
This parameter will not appear if ISE or ORP was selected as PRIMARY DISPLAY.
This section of the structure asks you to specify the buffers to be used if you are measuring pH
and will use the Automatic Calibration feature described on page 31.
In Automatic Calibration, the pH value calculated with values from the last calibration is used to
decide which buffer is in use. The algorithm checks each buffer starting with Buffer 1 and selects
the first one for which this pH is within 0.5 pH of the average pH for the buffer. You may select
between
AMERICAN, NIST, EUROPEAN, and SPECIAL buffers as standard buffer table
choices.
If you select SPECIAL, you must specify the number of points (NUM PTS) between 02 and 11
for Buffer 1, 2, and 3. The default value is 02. Each point specifies a value at a certain
temperature. The temperatures (TEMPx) can be specified from -99.9 to +999.9 (°C or °F) and