5128A
Operators Manual
32
Calibration
This section contains calibration procedures for the Product.
Calibration Principle
To calibrate the Product, the chamber is measured at a variety of temperatures
and relative humidity levels using a 70 % guardband to account for measurement
uncertainty. Temperature and humidity offsets are stored in the Product if
readings are found to be outside of the allowed tolerances.
The calibration settings order shown in Table 11 is optimized to give the fastest
Product stabilization times, and also to minimize the chance of condensation
during the calibration process.
Required calibration equipment is listed in Table 10.
Table 10. Calibration Equipment
Classification
Minimum Use
Specification
Recommended Equipment
Chilled mirror
hygrometer
0.1
°
C dew point
uncertainty
Michell Instruments S8000 Remote, or RH
Systems 473 with RP2 probe
Readout
0.006
°
C @ 25
°
C
thermistor uncertainty
Fluke 1586A Super-DAQ Precision Temperature
Scanner with DAQ-STAQ multiplexer
Thermistor
0.01
°
C calibration
uncertainty
Fluke 5611T 8 probes are required
Thermistor
probe fixture
Positions four of the
thermistor probes in a
square pattern at the rear
of the working area, and
the other four thermistors
in a square pattern in the
front of the working area
Custom wire jig
Calculator
Relative humidity
calculator
Thunder Scientific Humicalc®, Michell
Instruments Humidity Calculator, Vaisala
Humidity Calculator
Environmental Conditions
Laboratory environmental conditions required to complete this procedure:
•
Temperature range: 23
°
C
±
3
°
C
•
Relative humidity: below 60 %
Equipment Setup
Attach the chilled mirror probe and thermistor probes as shown in Figure 9.
Connect the thermistor probe to the thermistor readout and the chilled mirror
probe to the chilled mirror instrument.
