Soup in polyethylene bags exiting a chiller and entering the packaging line, monitored by Process Sensor?s infrared thermometer model PSC SSS-Laser.

The Application

In the Food Industry, plant cleanliness and maintaining a bacteria free product are primary concerns. To eliminate bacterial development, it is critical to maintain foodstuffs and processing equipment at temperatures below 41?F.

Truesoups, a division of H.J. Heinz Co., ( SIC code 209903 Food products ) provides frozen, ready to heat and serve soups. At its manufacturing plant located in Kent, Washington State, soup is conveyed in polyethylene bags to a chiller.

After exiting the chiller, the bags pass into the field of view of a Process Sensors model PSC SSS-Laser infrared thermometer with a spectral response of 8 to14?.

Clear polyethylene plastic transmits 90% of IR energy in that waveband. The spectral response also avoids the atmospheric moisture absorption bands that are present at either side of it. This feature can be important in food processing where steam and water vapor is often present.

At this time, the customer is using only the 4 -20mA output to display the temperature on an indicator, but according to Process Engineer, Dave Jametski, he plans to employ the Ethernet output for computer data acquisition using Process Sensor?s CompactConnect software package.

Jametski says that the stored data will be an essential tool in investigating product problems that often may only come to light after manufacture.

Application Tips

Food processing plants require some unique factors to be taken into account. First is the presence of steam and water vapor in the atmosphere. This may require air purging, but the source of air must be pure so as not to contaminate the product.? ? It is often better to use nitrogen for this reason.

If water-cooling is required, for meat cooking applications, care must be taken not to overcool, as this will cause condensation to form on the lens. The sensor should be positioned so that condensate does not drip onto the
product or the cooling flow must be regulated, thereby not exceeding the dew point that would cause condensation.

Food processes are frequently hosed down with hot water, or in some cases steam, so it is important to seal signal and power cable entry points. A long sight tube or gate valve can be used to protect the lens if necessary.

The Market

Applications for infrared thermometers in food processing are abundant and varied; from monitoring frozen fish on fish-stick cut up lines, to measuring and controlling sealing jaws on plastic bag sealing machines.

Processes are usually highly automated, with limited operator attendance, increasing the importance of monitoring, control and data acquisition instrumentation. OEM?s include continuous and static oven builders,
microwave and steam-kettle cooker manufacturers. Mixer and mechanical handling companies are also good prospects.

Process Sensors Model PSC-SS-Laser, with laser aiming defines the measurement area at any distance.

Instrument Selection

Process Sensors Model PSC-SS-Laser with a 75:1 FOV is used for continuous measurement at the chiller exit. Outputs: 4 -20mA, T/C and optional Ethernet.

Process Sensors Portable Model PSC-PSLT is recommended for hand held measurements.