Chapter 5

Materials and Methods

The most accurate commercially available humidity measuring devices have a precision of ±1.7% RH in the 95–99% RH range. This is not sufficient for monitoring and controlling the humidity during low-pressure (LP) storage because the error spans the entire range between a small water loss and extreme desiccation. During LP, a wet- and dry-bulb temperature measurement with ±0.05°C thermistors shielded from radiation with Mylar® is used to compute the chamber RH with an accuracy of ±0.1% at 99.9% RH. The wet-bulb measurement corresponds to the chamber dew-point temperature since heat transfer to the wet-bulb by convection is limited by the low chamber pressure, and Mylar® limits heat transfer by radiation. The RH ...

Get Hypobaric Storage in Food Industry now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.