Measurement & Monitoring
Measuring pH in a
food-safe environment
Inert Gas Blanketing in
Solder Reflow Ovens
In general glass pH electrodes are not suitable for food
applications due to the risk of broken glass fragments
contaminating the process. Furthermore, many designs
of pH electrode need to be removed from the process
stream before the CIP process can be completed which
requires expensive retraction systems to be employed,
creating extra work and inconvenience for the end user.
For the production of PCB’s, the reflow soldering
process is the popular choice of manufacturers,
allowing for the mass production of circuit
boards with intricate surface mount component
soldering to the highest quality. Heat generated within the oven melts the solder and
with the aid of solder paste, solders the components to the PCB. Quality is further
improved by introducing the use of nitrogen within the oven to create an inert
atmosphere. Nitrogen gas blanketing reduces the risk of oxidisation and improves the
wetting angles of the soldered joints, therefore increasing the reliability of the product.
One solution could be the Type 8201 pH measuring system, which employs a hygienic,
robust and glass-free design that can withstand high temperatures and can be
sterilised in situ. In addition, the smooth enamel external surface of the probe inhibits
the process medium from sticking to it and is very easy to clean.
The wide variety of manufacturing processes in the food industry that require pH levels
to be monitored and controlled means that sensors need to selected accordingly to suit
each application. Media purity, temperature and pressure all need to be accounted for
as well as portability and calibration frequency. All of these areas should be carefully
considered along with expert technical advice from manufacturers such as Bürkert.
The inert atmosphere within the oven is maintained by the use