E-Zine December 2016
Click here to read “The Vendor Relationship (Part 1)”
Here’s where it often breaks down. Many users are simply not willing to see that the problem isn’t with the equipment the vendor provided, or with the control system the equipment is tied to, but rather is an application problem. These users generally want, either to throw a new meter at the problem, or to make the vendor fix the application. Neither of these is an effective response strategy. Rightly, most vendors take the position that replacing the meter under warranty, or providing a different meter, is not the right way to proceed. Most vendors track the number of times a customer has reported a problem over the last few months, so that they can spot trends. Sometimes, the trend they spot is a previously unreported manufacturing defect. Often, it is a user error, in operation or application.
Many years ago, a gas chlorination company changed their injector nozzle’s throat design from a taper, which was hard to make and required complex machining, to a step-cut orifice, which worked just as well, and could be injection molded. A customer started having a very high level of injector failure. The injector nozzles kept breaking. On inspection, I finally discovered that the operator didn’t think that the step-cut orifice was a good thing. So being a good machinist, he would take the new nozzle out of the parts bag, put it in the lathe and “touch it up” before installing it.
But what do you do as a user if you have done everything the vendor says to do and the vendor agrees that it isn’t an application problem, and the vendor won’t or can’t provide the service you expect?
Sometimes, in situations like these, when I worked for a vendor I simply brought the product back, and gave a full refund. If I can’t figure out what the problem is, and I’ve had the device back at the factory several times, and I’ve had reps and tech reps out looking at it, this is sometimes the best solution.
Not all companies will do this. Sometimes you have to push them to give you what you want.
When you have decided that the vendor is being completely non-cooperative, start by talking to the local rep or distributor. They have a vested interest in seeing you satisfied, since they usually have more things to sell you, and a long-term relationship with you to protect. Get them to act as your ombudsman at the factory. This usually works because they know the phone numbers of the people at the top.
From Flow Control (February 2002)
Quiz Corner: Doing What Is Right
By David W. Spitzer
E-Zine December 2016
Some flow problems transcend flow measurement. As a professional in flow, it is likely that you have come in contact with people who are more skilled in other areas. Sometimes these individuals will be positioned as your boss, or have appointed themselves as your mentor, whether or not they are qualified for these roles. My son was recently confronted with such a situation.
Somewhat frustrated in his first year in college because he was forced to take courses in his major that he could have easily taught, he stretched himself by taking graduate classes in his second year. A teacher (who objected) examined one of my son’s recent projects. In front of other people, this teacher tactlessly and brutally described how he (the teacher) would have done the project while neglecting to praise any positive aspect of the work. The criticism was so harsh that certain parts of the work were characterized as “wrong” and “arrogant”. If you were the student, would you:
A. Tell the teacher why the project was not incorrect.
B. Listen to the teacher and make changes that conform to the professor’s ideas.
C. Listen to the teacher and not make changes.
D. Listen to the teacher and later confront the teacher privately.
E. Listen to the teacher and speak with a family member for advice.
F. Listen to the teacher and speak with another faculty member for advice.
G. Bring the event to the attention of the department head.
The student attempted to tell the professor why the project was not incorrect (Answer A), but the teacher did not seem to listen to logic. Answer D would likely be ineffective because the teacher had already been confronted regarding the practice of humiliating a student in front of peers and staff. Answer G would be making too much of the situation.
In a logical world, redesigning the project using feedback from the teacher would seem reasonable (Answer B). However, speaking with a family member (Answer E) revealed that it was “unusual” for a teacher to hold a student back, and likely that the teacher had a problem that transcended the technical aspects of the project. If this were the case, redesigning the project to conform to the teacher’s ideas (Answer B) could be a potential setup for failure. Therefore, it was decided to incorporate reasonable changes into the project, and avoid the teacher until the student could speak with a trusted adjunct faculty member who worked in the industry and not solely in academia (Answer F).
The adjunct found only minor problems with the project that did not form a basis for the harsh criticism that the student received. Having attended the same prestigious graduate school, the adjunct was able to provide insight into the teacher’s behavior --- the teacher was emulating the intimidating and confrontational manner in which he had been taught in graduate school. Further, the adjunct recalled that many teachers had conflicts with students who had potential and who aggressively pursued their education. As a result of these conversations, my son has a better understanding of these situations, and is giving more thought as to the appropriateness of what had been his preferred graduate school. The project will be completed as the student sees fit using reasonable input from the teacher.
This situation commonly occurs in industry --- a boss or supposed mentor who uses intimidation tactics to achieve an end that may somewhat questionable. There should be a clear understanding that doing what you are told and doing what is correct may not be the same --- and that doing either can cost you your job. Independent of your current stature in your field, a trusted mentor and the willingness to judiciously consult with that mentor in his/her field of expertise can be an invaluable professional and personal asset.
Additional Complicating Factors
These events occurred in the “sheltered” confines of a university campus. How would you handle this situation if the boss or mentor were related to an owner of the company?
From Flow Control (May 2002)
Quiz Corner: Flowmeter Performance Claims
By David W. Spitzer
E-Zine December 2016
As I rifled through a report that I wrote some time ago, the section about manufacturer performance claims caught my attention. It was only 2.5 pages long and had three subheadings --- high turndown, low flow operation, and high accuracy --- yet its importance cannot be overstated. How would you respond if a manufacturer claimed that a certain flowmeter had a 1000:1 turndown, operated down to 0.01 meters per second (0.03 ft/sec), and performed with 0.25 percent rate accuracy?
A. Agree that the flowmeter is excellent and consider its purchase.
B. Question technical aspects of the specifications individually.
C. Question technical aspects of the specifications collectively.
D. Escort the vendor to the gate, because no flowmeter can meet these specifications.
I rarely accept manufacturers’ claims at first glance (Answer A), even when the manufacturer may be known, reputable, and knowledgeable. This applies to any performance claim, even poor ones --- I recently questioned a 5 percent of full scale flowmeter specification. Escorting the vendor to the gate (Answer D) is perhaps an extreme response because the manufacturer may actually have invented a better mousetrap.
The next step is to question the technical correctness of the individual claims (Answer B) before considering the claims collectively (Answer C). Discussions revealed that the magnetic flowmeter did have a 1000:1 turndown, operated within specification for flows as low as 0.01 meters per second, and had an accuracy of 0.25 percent of rate. The implication of these “facts” is that the flowmeter can measure within 0.25 percent of rate over a 1000:1 turndown on flows as low as 0.01 meters per second.
However, further discussions revealed that although each of the claims was true when viewed independently, the implication of excellent accuracy over a wide range of flow did not follow when the claims were considered collectively. The flowmeter accuracy was 0.25 percent of rate, but only for flow velocities above 0.2 meters per second. Below 0.2 meters per second, the absolute error was 0.0005 meters per second. So at 0.01 meters per second, the error is 0.0005/0.01, or 5 percent of rate. In other words, the flowmeter operates over a 1000:1 range of flows and will measure accurately at 0.01 meters per second, but measuring accurately at 0.01 meters per second means within 0.0005 meters per second, not within 0.25 percent of rate. Therefore, flowmeter performance (as a percentage of rate) at low flows could be degraded by a factor of up to 20 and still perform within the stated claim of 1000:1 turndown.
This is not to imply that this particular flowmeter does not perform well. Actual comparison with other flowmeters will reveal this performance to be superior to most other flowmeters of its type. The point is that one should interpret the claims collectively in order to understand the actual performance, and not rely on “tidbits” of information --- even when they are true.
Additional Complicating Factors
Flowmeter accuracy is usually predicated upon the pulse output. Use of the analog output introduces an additional absolute error that complicates the above analysis.
From Flow Control (June 2002)