How does it work?
The corrosion meter uses the linear polarization resistance method of calculating corrosion rates. Since corrosion is an electrochemical reaction, we send an electrical impulse down one side of the corrosion meter probe and the metal tips at the end of the probe then measure the corrosion rate through a measure of the “electrical noise” generated by this electrical impulse.
The corrosion meter then displays the corrosion rate in terms of mils per year. The mils per year reading is the same information that is reported during the use of corrosion coupons. For example, 5.0 mpy is 0.005 inch per year metal loss. In 20 years, 5.0 mpy equals one tenth inch metal loss over that time period.
How is this an improvement on Corrosion Coupons?
Obviously many changes can take place in the corrosion rate during a 90-day period. The corrosion coupon only provides an average rate of corrosion over the 90 days, while a corrosion meter monitoring program can provide us readings once a minute. By comparing the corrosion meter readings over a 90-day period, we can plot out multiple data points in comparison to just one reading provided by a corrosion coupon during that same time period.
Can this help me monitor seasonal fluctuations?
Corrosion rates during cold weather months are typically lower than corrosion rates during warm weather months. A lower feed rate during months when the water is less corrosive offers savings, while a higher feed rate during months when the water is more corrosive offers control of corrosion rates when needed the most.
I use LSI, how is this different?
Langelier Saturation Index provides an indicator of the degree of saturation of water with respect to calcium carbonate and does not measure the corrosion rate of water on metals. With LSI we can only predict the nature of scaling but quantification cannot be calculated.