Designing a Wireless Temperature Sensor for meat processing

The process used for cooking and meat processing in an industrial process is a very rigorous one.  The meat has to be cooked to a certain temperature to ensure the safety of the product, and done on a large scale to optimize efficiency of production.  Internal temperature sensing is how the industry ensures that all the food is cooked to the right temperature.  This process is easier said than done.  Typically, a wired probe is placed into the meat and read every minute, according to FDA regulations.  These probes have a major shortcoming.  The cable that gets damaged frequently.   Matrix Product Development has designed a wireless temperature probe that senses the temperature.  Designing this temp probe came with many challenges of its own.

Inserting electronic equipment into any extreme environment leads to unforeseen problems.  The probes have to withstand the heat of the oven and the cold water used to cool the meat at the end of the cooking cycle.  When batteries and microchips undergo changes in temperature (i.e., operating well above or well below room temperature), they do not operate at their ideal conditions.  Ensuring that the batteries and chips worked correctly in a range of temperatures is a major challenge.  Additionally, the temperature changes quickly.  The probe sits in a high humidity, high temperature oven while the meat cooks and when cooking is complete, it is rapidly cooled down with chilled salt brine.  This very rapid change in temperature creates a vacuum effect inside the electronic temperature probe that caused by the contracting air inside the temp probe.  If the probe leaks and water gets in, the probe is useless and needs to be replaced.

The probes also have to go through the rigors of typical industrial equipment.  They are exposed, as mentioned before, to rapid temperature changes and high heat and humidity of the ovens.  They are also dropped on the floor, exposed to cleaning chemicals, and other things that might happen in a factory setting.  The probes need to go through all these environments, and still stay sealed and calibrated correctly to ensure proper temperature readings.

Even if the probes are reading the temperature correctly, transmitting and collecting wireless signals in very humid places is very difficult to do.  The water vapor causes signal attenuation shorting the read range.  The frequency or the signal being transmitted has to be chosen carefully to ensure that this attenuation is not to detrimental to the signal so proper signal to noise ratio is achieved.

Engineers at Matrix Product Development worked close with the meat processing industry in order to ensure that their wireless temperature sensors met all these requirements and worked effectively in this harsh environment.