Research for The Consumer Guide to Non-Contact Level Gauges
extracting information from the level gauge specifications from
about 60 suppliers. These suppliers used a total of about 30
different terms to express performance. Let's think about this
for a minute --- on the average, there was one term used to express
performance for every two suppliers. This would seem to be far
In the early going, the well-defined published specifications
were tabulated and used for calculations. As research progressed,
conversations with suppliers made it apparent that the published
specifications could not be trusted --- even if they were
technically clear and well understood. As a result, I had to
contact the suppliers again to verify that their (supposedly)
well-defined published specifications reflected the supplier's
For example, after speaking with the suppliers, 0.25% of measuring
range, 0.25% of span, and 0.25% all meant 0.25% of maximum sensor range.
Think about this for a minute. Measuring range and span are well defined ---
or are they? The percentage is not well defined and begs the question,
"Percentage of what?"
On a positive note, despite the discrepancies noted in the published
specifications, suppliers were forthcoming in explaining their intentions.
Wouldn't it be nice if they would update/correct their specifications to
use standard terms that describe level gauge performance?