BetaGauge330

In June, we started shipping the BetaGauge 330 with available absolute pressure internal sensors. The 330 is now available with a 30 PSIA (2 barA) or a 150 PSIA (10 barA) internal sensor.

The new ranges offer the same ±0.025% of full scale accuracy (6 month specification) as the previously offered gauge ranges (30, 150 & 300 PSI).

Some of the other useful features of the 330 are

• built-in loop calibrator (input and output
• large multi-variable display
• 24 VDC instrument power supply
• automatic pressure switch test
• available gas custody meter calibration kit
• 17 engineering unit displays
• external pressure module compatible

For a surprisingly low cost in a surprisingly small and lightweight package, the BetaGauge 330 has a lot to offer.

We (people actually in the calibration industry) often hear things being called calibrators that obviously aren’t. A great example is the Emerson HART(tm) communicator. No offense intended, but these types of devices aren’t calibrators, they are electronic “screwdrivers” that enable a technician or engineer to adjust the calibration of a device.

Here are my defining points for a calibrator.

1. Can make a precision measurement or generate a precision signal (i.e., analog, not digital). Or BOTH.
2. Has a calibration that is traceable to national standards.
3. Has a known accuracy or degree of calibration uncertainty.

There is a lot that could be added to this list, of course; things such as conformance to international standards, EX ratings…

Another little list of mine is this list of characteristics that make up a good calibrator.

• Accuracy
• Flexibility or versatility
• Ease of use
• Reliability
• Ergonomics (small, lightweight, easy to read display, etc.)
• Value

To me, a great example of all of the above is the Martel BETA MC-1200 Multi-function Calibrator. It’s got a long list of features, top knotch performance and is a great deal for the money. Total cost of ownership is good because all they ever require is annual recalibration which anyone with a computer and adequate standards can do.

Martel calibrator user Bruce Schmeck is quoted in the March, 2010, issue of Control Magazine saying, “We use field calibrators…for all kinds of biochemical batches to monitor and verify temperature, pressure, flow and agitation.”

In the same article, one of our competitors surveyed users and unsurprisingly discovered that a lot of them aren’t calibrating the instruments in their plants.

The article goes on to point out that many users have been sold a bill of goods about their instrumentation from the makers of that instrumentation. To wit,”our digital instruments don’t drift, so they don’t need to be calibrated.”

BetaGauge 321A Dual Range Pressure Calibrator

Mr. Schmeck also explained in this article that it isn’t the digital part of new instruments that drifts; it’s the part where the rubber meets the road, so to speak. He cites the example of the metal diaphragm in a pressure transmitter. The metal will age and its response characteristics will change over time. The ONLY way to fix that is to use a traceable field calibrator to inject a known valid signal.

To sum it up, here’s another quote from Bruce Schmeck that I like, “Most calibrators need to be re-calibrated once per year.” I love it.

I’m not referring to an old time game show or parlor game as they used to be known. My question is, “Can you trust your vendor’s calibration certificate?”

There are a few indicators you can use.

1. What kind of reputation does the company have in the industry? You know, how long have they been around and do other customers respect their products and service? There are a number of industry surveys and reports that can help with this if you don’t feel comfortable making your own assessment.
2. Is the certificate traceable to NIST or other national standards body? This may seem obvious, but read the statement see if it makes sense to you. Are there unsupported assertions about things like TUR (Total Uncertainty Ratio) or Guide 25 approval?
3. Are the standards used properly identified and are they appropriate for the task at hand? For example, if a specification is % of reading, but the standard’s specification is % of scale, there’s a significant mismatch. You may also need to check to see if the standard has been properly maintained with acceptable calibration intevals.
4. Does the certificate include data that is clearly presented and meaningful? Are there sufficient data points to assess performance?
5. If possible, check the calibration at intervals different from the cardinal points on the certificate. Even a bump check can provide revealing information.

Finally, is the calibration accredited under an international standard (ISO 17025) or do you need such an accredited calibration. Even if it’s offered as an option, the vendor must have a pretty good idea that the normal calibration is valid.

We have updated the very popular and powerful BetaGauge 311 and BetaGauge 321 Advanced Pressure Calibrators. The new models are the single range BetaGauge 311A and dual range BetaGauge 321A. What we didn’t change are the great performance and ease of use we already had.

Here are the new features:

• Super rugged “Power-Tool-Tough” housing. We’re using the same plastic used in high end cordless drills and the like to make the BetaGauge 311A/321A virtually indestructible.
• Custom engineering units. If you don’t like any of the 19 built-in engineering units, you can configure up to 2 additional units. If you give us the factor information and unit name at the time of order, we’ll even put it in for you at no extra cost.
• Enhanced measurement stability. We updated the circuit design on the pressure sensors with our latest technology to provide better all around performance over a wide range of temperatures and with less long term drift.
• User selectable resolution. Sometimes, there’s too much resolution for the intended application. Those extra digits can make the job harder not better. So, you can reduce the displayed resolution by a single digit in any application.
• More compatible ranges. With 29 possible ranges, we let the user choose what’s right for them. Now, we’ve made the ranges more compatible with long time industry practice by providing compound measurement on most ranges below 500 PSI (35 Bar).

See our web site for more details. The new calibrators are available NOW!

Some of our competitors like to brag that by offering a percent of reading accuracy specification, they give better down scale performance than our percent of full scale specification. The problem is, that’s really not true.

For the case in point, we’re talking about digital test gauges. Their very nice gauge has a specification of ±0.1 % of reading plus a minimum or floor error of ±0.02% of full scale. Our standard BetaGauge PI has a specification of ±0.05% of full scale. Here’s a chart so you can see how these gauges stack up.

So, the percent of reading does do better below 50% of scale, but above that, it’s no contest. AND, the normal use of gauges will be in the range above 50% of full scale.

However, if you do think you’ll need better down scale performance, why not look at the cost effective BetaGauge PIR Reference Class gauge? It offers better performance across the board at a comparable price. Here’s how it stacks up.

For more information about the BetaGauge PIR Reference Class gauge, please visit our web site.

PS – to get a better look at the charts, just click on them. The blog shrinks it down and makes it fuzzy looking.

Since Martel is introducing a new BetaGauge at the ISA Show in Houston (October 14-16), I thought it would be a good idea to give you a short history of the BetaGauge calibrator line. (Note, this blog was first posted on Friday, September 12^th, but due to a technical glitch, it was lost).

The immediate predecessor of the original BetaGauge was a little calibrator called the DPG-310 from BETA Products. This was licensed from RiS (Rochester Instruments). It was a gauge only. That is it could only measure pressure. It handled the temperature sensitivity of the silicon sensor by enclosing it in a little “oven” that kept the sensor at a constant temperature. I think the temperature was about 40°C. This was in 1989, so I don’t remember all the details. The accuracy was ±0.1% of full scale as I recall. It had a tiny 2 line by 16 character LCD display. Although pretty good for its time, it suffered from a couple of problems, both related to the “oven.”

First, the relatively high temperature prematurely aged the sensor, resulting in a shortened life. Second, the power to run the heater sucked juice out of the batteries quickly.

So the improved BetaGauge 320 was conceived with better battery life (nearly 100 hours continuous use), dual ranges and characterized sensors so changes in ambient temperature weren’t much of a problem. Although it wasn’t an immediate success, it was so much better than its main competitors the old Crystal Engineering and Meriam calibrators, it did get to a point where monthly sales exceeded more than 100 units for a couple of years. It had better resolution, a better display and 2 available ranges.

Another point in its favor was the wide number of ranges from 10” WC full scale to 5,000 PSI full scale. It could also do true differential measurement and absolute measurement. As it has turned out, it was pretty rugged and reliable, too. We continue to have customers send theirs in for calibration and repair. Many of these units are more than 10 years old. Even with a nice trade-in offer, they don’t want to give up their old friend.

BetaGauge II

That being said, users did complain about some deficiencies in the 320. The major complaints were: lack of interchangeable ranges, lack of replaceable batteries and the small dark display (2 lines by 16 characters LCD). Hence, the BetaGauge II, which was released in 1994.

The BetaGauge II was the first handheld pressure calibrator with a fully modular interface. Changing the pressure range was as simple as plugging in a different pressure module. Also, the modules were the calibrator. The handheld part did not require any service or recalibration.  It started off a little slower than expected mostly because we were unable to produce the large number of ranges we had for the 320. Also, at first, we did not have an IS rating for it.

The really big news for the BetaGauge II wasn’t the large bright display, the interchangeable modules or the replaceable battery packs. The big news was that it was the first handheld pressure calibrator to offer ±0.025% of full scale accuracy for pressure. That was needed as field pressure transmitters were becoming much more accurate and calibrators up to then had not kept pace.

Part II of this series will continue with the BetaGauge 321 story.