Michell Sensor Controls Humidity For Bread Making

A European food processing manufacturer has chosen Michell's PF211 relative humidity (RH) transmitter to control humidity and temperature in its range of fermentation chambers. Designed for small-to-medium bakeries, fermentation chambers provide a consistent environment for bread dough and yeasted products to rise and prove. The cabinets are insulated with air-conditioning systems to accurately control both temperature and humidity as well as a flow of fresh air.

Previously, in small or artisan bakeries, mixing, kneading and fermentation would be a manual process. The development of these cabinets enables the automation and regulation of part of this process and is said to ensure more consistent results. The challenge for the manufacturer is to reliably control humidity across the wide range of temperatures required in bread making, from proving (rising dough at a warm temperature) to retardation (where bread dough is kept to rise at a low temperature for up to 12 hours to develop flavour).

The PF211 probe was chosen because of its wide measurement range - from zero per cent to 100 per cent RH and from -30C to +70C. The sensor is stable with +/-1 per cent RH drift a year, ensuring reliable results over a long period of time, according to Michell. To facilitate maintenance, the PF211 uses the I7000 Hygrosmart interchangeable module. The sensor head incorporates all the calibration data; to ensure continued reliability over time, the user can replace the old sensor with a new one.