5128A
Operators Manual
24
For short probes without an available cable, insert the probe into the door as far
as possible and do calibrations at or near ambient temperature. This eliminates
temperature gradients between the UUT and the chamber. Under these
conditions, where the UUT probe is not fully immersed in the working volume, an
external reference probe that is inserted at the same depth should be used to
ensure the best calibration.
Stabilize the Chamber and UUT
The Product response time is normally much faster than that of the UUT, with
typical stabilization times <5 minutes between typical UUT verification points.
However, to ensure that the UUT temperature and humidity is at equilibrium with
the chamber conditions, allow for stabilization times of at least 15 minutes
between set points. Longer stabilization times may be necessary if the initial UUT
temperature is significantly different than the chamber temperature and if the
chamber is set to extreme humidity and temperature set points. Monitor the
actual temperature and humidity points as shown on the Product display.
Chamber stabilization is typically reached when the actual temperature is within
0.1
°
C of the set temperature, and the actual humidity is within 0.2 % of the set
humidity.
Data Logger Calibration
To calibrate Data Loggers:
1. Place them directly into the calibration area of the chamber and use the clear
glass door and the shelf accessory. See Figure 4 for approximate placement.
ibw025.eps
Figure 4. Data Logger Placement
2. Put the UUT into its data logging mode, and then set and record the actual
calibrator temperature and humidity at known points in time.
3. Compare the UUT logged data against the actual Product temperature and
humidity settings.
For data loggers that are too large to fit inside the mixing
insert, but fit inside the outer chamber, the larger shelf can be used to hold
the UUT. Use an external reference probe to monitor the conditions of the
Product.
