WIKA CTD9300 - Handbuch (Seite 28)

9037926 03/2005
Temperature Dry Well Calibrators CTD 9300
3. Moduses and Functions
GB
28 WIKA Operating Instructions CTD 9300 Rev. 1
within the operating range of the calibrator.
The resolution is 0.01 K.
The individual temperature ramps are serially numbered from 1 to 6.
If the "UP" function is enabled, the ramps are approached in the
order 1, 2, 3, 4, 5 and 6. If the "DOWN" function is enabled, the
ramps are approached in the order 6, 5, 4, 3, 2 and 1. If both
functions are enabled, the ramps are approached in the order 1, 2,
3, 4, 5, 6, 5, 4, 3, 2 and 1. Disabled ramps are skipped.
Gradient
Using the gradient function, defined heating and cooling of the
calibrator can be set. The value for the gradient is set in K/min with
a resolution of 1 K.
The upper ramp for the gradient is determined through the heating
power of the respective device. This means that the device with the
gradient function enabled cannot heat at a faster rate than with the
gradient function disabled. The gradient function is primarily used
for checking temperature switches. To prevent the switch point of a
temperature switch from being exceeded during heat-up, the
calibrator is heated only slowly. Gradients between 1 K/min and
5 K/min are typical. Especially for temperature switches with large
immersion tube diameters, this prevents that the temperature of the
switch lags behind that of the calibrator.
Tolerance and Duration
Using the Tolerance and Duration functions, the stability and
length of the dwell time on a temperature ramp can be set. If the
dwell time is to be 5 minutes with a stability of ±0.1 K after the
nominal temperature has been reached, the duration must be set to
5 min and the tolerance to 0.1 K. In this case, the timer will start
when the actual temperature differs by less than 0.1 K from the
nominal temperature. If the temperature remains within this
tolerance for 5 min, the time period for the next ramp will be
approached after the present time period has elapsed. If
fluctuations occur during this time that exceed the set tolerance,
the timer is reset and restarted. When the tolerance has been
reached, TEMP. STABLE is displayed in the status bar.