David W. Spitzer

For the past few months, I described problems with a new installation of an insertion vortex-shedding flowmeter. (See “Applications Corner” – Feb., Mar., May.) Not only were the physical properties of the liquid specified and configured incorrectly, but the flowmeter was installed in a different size pipe as well. If you have been around for a while, you have undoubtedly seen similar problems where specifications are incorrect, configuration is incorrect, and/or the device is not installed as planned.

Looking back, this application and installation had multiple problems, but you might not think that to be the case if you followed the issues in sequence. First, the flowmeter was reported to be measuring low. Apparently nothing else was wrong, but after the flow measurement was corrected, the flow measurement repeatedly dropped out. My client initially observed both symptoms, but he chose to initially report only the measurement error as a problem.

The second problem (drop out) was not mentioned until the first problem was resolved. Had my client mentioned the second problem in conjunction with the first problem, he would not have had to expend as much time, effort and resources to have a technician visit the plant to obtain information that was relayed to the representative and, afterwards, to the factory. Similarly, the factory would not have had to diagnose the first problem only to be confronted with a second problem that rendered the flowmeter marginally operational in this application.

Situations where more than one problem exists are typically more difficult to identify and resolve than their single-problem counterparts. This can be especially frustrating when one of the problems turns out to be fatal to the application, such that the instrument will not work. Be sure to question people completely and train them to share all of their observations with you – this will allow you to better help them.

David W. Spitzer is a regular contributor to Flow Control with more than 35 years of experience in specifying, building, installing, startup, troubleshooting, and teaching process control instrumentation. Mr. Spitzer has written over 10 books and 150 technical articles about instrumentation and process control, including the popular “Consumer Guide” series that compares flowmeters by supplier. Mr. Spitzer is a principal in Spitzer and Boyes LLC, offering engineering, expert witness, development, marketing, and distribution consulting for manufacturing and automation companies. He can be reached at 845 623-1830.