Specialized, highly accurate pressure and temperature transmitters are crucial for piping, filters and tanks in the food, beverage, dairy and pharmaceutical industries. Food and beverages must be produced and stored at very specific temperatures to maintain their quality and safety, so the hygienic design of food and beverage plant components that come in contact with products is essential for avoiding contamination.
Measuring instruments used in these applications must meet specific requirements, including construction material, surface quality, shock resistance and connection type.
These markets also require sensors that can withstand the rigors of clean in place (CIP) and sterilize in place (SIP) cleaning, provide rapid temperature recovery, digital outputs and utilize specific wetted part materials depending on the media being measured. CIP cleaning is used to clean the interior surfaces of kettles, pipelines and tanks of liquid and semi-liquid food and beverage processing equipment.
Most sensors in these industries utilize a flexible diaphragm as the pressure sensing element. Flush mounted pressure transmitters have no cavities and are easy to clean.
A transmitter’s wetted parts are those which come into contact with the medium being measured. The wetted parts must have smooth edges and clean welding with no small spaces where media can collect and rot. Generally, wetted parts for these sensors are constructed from 316 Stainless Steel to prevent media from sticking.
Transmitters for these industries that are designed with the pressure and temperature sensors mounted directly behind the diaphragm have distinct advantages. This design minimizes fill fluid and allows the use of a smaller diaphragm to active temperature compensation at the point of measurement - minimizing temperature and position error. In addition, transmitters with high turndown ratios allow greater rangeability, minimizing required inventory.
Pressure flow through the process pipelines must be monitored to detect blockages in the pipes. During transportation, food and beverage products need to be contained under certain specified conditions. Accurate control and pressure/temperature measurement of the entire process from manufacture to delivery is therefore crucial. Low temperatures could compromise hygiene and product safety, and high temperatures result in wasted energy and higher costs.
Typical Food Sensor Applications include:
Ultra Heat Treated (UHT) Milk – Billions of tons of milk are used in the production of a wide variety of products annually, including yogurt, butter, cheese, sour cream, cottage cheese etc. While the production process for each of these foods varies, they all include multiple stages of heating and cooling the milk. Maintaining consistent milk temperature throughout this process is critical to producing a high quality and safe product.
Tank Level (Storage) – Food and beverage products are stored in holding tanks during production. Accurate pressure and temperature measurement of storage vessels provides a record of on-hand inventory.
Specialty Baking – Continuous control of temperature in the very large ovens used in industrial bakeries is key to producing high-quality taste and product appearance. To achieve this, these ovens incorporate transmitters in multiple locations.