The switch-off criterion
The switch-off criterion (AK) determines the point at which measurement with the Halogen Moisture Analyzer is automatically ended and the result displayed. The Halogen Moisture Analyzer offers two different kinds of switch-off criteria: A time-controlled form of switching off or the decrease in weight per time unit. The integrated balance continually determines the loss in weight of the sample during drying. If the loss in weight (Δ g) falls below the prescribed figure over a certain time (Δ t), the drying process is terminated at this level of dryness
and the result displayed. You can select from 5 pre-defined switch-off criteria.
- AK 1 (1 mg/10s): Suited to quick trend measurements
- AK 2 (1 mg/20s): Intermediate level
- AK 3 (1 mg/50s): Standard setting, suited to most types of sample
- AK 4 (1 mg/90s): Intermediate level
- AK 5 (1 mg/140s): Suited to samples that dry slowly and have a low moisture content (e.g. plastics)
With the HR83 Halogen Moisture Analyzer, the time period and desired weight loss can be freely defined.
The switch-off criterion selected influences the measurement period and measurement accuracy. The drying process will be completed in the shortest time if AK 1 is selected, but the drying is then often not fully finished and repeatability
is reduced. By selecting the switch-off criterion you optimize the duration of the measurement period against the required accuracy
of the measurement result.