Operation
5.4 Operating functions
OXYMAT 64
Operating Instructions, 06/2008, A5E00880383-03
101
A distinction is made between joint and separate parameters. Joint parameters apply to both
dimensions, separate parameters are different for the vpm and % v/v ranges. The following
are listed separately:
● Measuring range start-of-scale and full-scale values
● Number of valid measuring ranges
● Selected measuring range with autoranging
● Calibration gases for measuring ranges and zero
● Selected MR calibration gas
● Limits; switching direction of limits
● Measuring range validity of limits
● Limit monitoring on/off
● Format of measured-value display
● Start and end values of characteristic
The following are listed jointly for both dimensions:
● Total deviation of zero point and measuring range calibration
When switching over, the following parameters are recalculated to the new end values of the
characteristic:
● Measuring range calibration factors
● Post-compensation factors at the zero point below and above the reference temperature
● Start value of post-compensation at the zero point
● Interfering gas deflection value with correction of cross-interference
0-99999 is set in the vpm range and 0-100 in the percentage range as the end values of the
characteristic. Several calibrations, compensations and linearizations are influenced by
these values. Therefore all calibrations, compensations and linearizations must be
redetermined following a change.
The change in dimension takes place in less than 1 second. The analog current output is
instable during the change, and the measuring range limit relays etc. are also influenced.
This is usually irrelevant since the measured value changes strongly when an automatic
change is carried out, and the measuring range also probably changes. Furthermore, this
effect can be reduced further by appropriate selection of the measuring ranges.
Changing the dimension via a binary input is not possible. These values are switched to
active depending on the current dimension.
Automatic changing of the dimension with a defined hysteresis can also be selected. It
switches over when the following values are reached:
● From vpm to % v/v when the measured value exceeds 50000 vpm
● From % v/v to vpm when the measured value drops below 2%
The automatic changeover is prevented during a calibration.
As an option, you can activate the functional check during changing of the dimension. This is
then active for approx. 10 seconds. This guarantees that the measured value is only enabled
again when all limit relays have been correctly set again. Since these are parameterized
independent of one another, they can briefly output incorrect values if the functional check is
not activated.