The continuous measurement of moisture
prior to packaging is a key consideration in the production
of potato chips. The proper moisture level of finished chips
helps guarantee taste, texture and shelf life.
The use of NIR (Near Infrared Reflection) moisture gauges
in snack food manufacturing environments has become an accepted
technology for monitoring and control. The on-line measurements
are instantaneous and non-contact. Any change in moisture
level can be immediately recognized by the use of a Process
Recorder, eliminating the potential for customer quality complaints
NIR can also be used to measure oil content, along with moisture.
The oil measurement is most often done at-line as a quality
indication prior to packaging.
Chip Manufacturing Process
Potatoes are peeled, sliced and de-starched prior to Frying
and Seasoning. Measurements of oil and moisture are typically
made shortly after the exit of the Fryer. Moisture measurement
at the exit of the Fryer can be used to optimize moisture
%, this results in greater product consistency, longer shelf-life
and less waste material.
PSC moisture transmitters should be located after the fryer
outlet, over the vibrating conveyor. The transmitter should
be mounted 10” from the surface of the potato chips.
Heat at the fryer outlet can create very high temperatures.
If the transmitter must be located close to the outlet of
the fryer, it is important to consider cooling.
The MCT330SF moisture transmitter is designed to measure
moisture, oil and product temperature in a food processing
environment. The transmitter is housed in a stainless steel
enclosure and employs a food grade optical window. The MCT
is optimized with filter combinations to measure moisture
and oil at the same time. The viewing window in the sensor
is a food grade polymer. The stainless steel housing is sealed
so that the NIR sensor can tolerate a wash-down environment.
The MCT-330SF is fitted with an air purge assembly to prevent
oil or moisture from depositing on the sensor’s lens.
The Stainless Steel Enclosure can also be fitted with a Vortex
cooler in the event of a very elevated temperature environment.
Moisture measurement in potato chips is a very well understood
and documented application. NIR wavelengths, algorithms, and
sensor optical parameters are pre-set at the PSC factory.
A calibration is entered into the MCT-330SF at the PSC factory.
There is no calibration required after installation on the
It is important to locate the MCT so that there is always
product beneath the NIR sensor. The measurement works by detecting
reflected light. The light must be reflected off of the product,
not the vibrating conveyor!