Errata for The Barometer Handbook

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p.22

in Figure 2.1-2  the outside arrows point in the wrong direction

merry-go-round is rotating in the counterclockwise direction for the ball to move as shown.

p.67

Figure 4.3-2 inserted formula is not correct.

 

The goal is to weight the data such that closest station counts more in the average. One rough way to do this is use the formula from Fig 4.3-1 for each of the 3 pairs of stations and then average that result.... but still that is not fully correct.

The formula we intended was:

P = (d2d3P1+d1d3P2+d1d2P3)/(d2d3+d1d3+d1d2)

But since we have the bearings, the best solution will be a more complex result, which we can program and put online as a form. Enter the data and we compute the proper average for you. This way we can compute the local pressure surface based on the nearest data, regardless of their distribution relative to you, and extend it to your location to find an average. Please check the website periodically to learn when this is implemented. www.starpath.com/barometers.

p 79-80

additional source of US calibration. This is a long established company. we simply missed them in our survey of these services.

Add: Mensor Corp. in San Marcos TX offers barometer calibration service for their own and other brands as well. Price is about $390, which includes a report of "as found" and "as left." Turnaround time of about 2 weeks.

Chapter 7

we failed to include an important practical application of accurate barometric pressure

Oncology labs around the world need to know the accurate atmospheric pressure in order to calibrate some designs of radiation detectors. Generally they need a minimum of ±1mb accuracy.

The standards and requirements are presented in a protocol written by Task Group 51 (TG-51) of the
Radiation Therapy Committee of the American Association of Physicists in Medicine (AAPM) and
has been formally approved by the AAPM for clinical use. The document is referred to as AAPM TG-51.

Chapter 6

We have greatly expanded our experience with barometer calibrations over the past 2 years, and the next edition will include more emphasis on this detail we have learned...

most moderate-cost electronic barometers are adjusted to be as close as possible in mid range, but many of their calibration curves deviate at the extremes of the pressure ranges... i.e. above 1030 and below 990. With a measured calibration curve in hand this does not matter, but without calibration the instrument will be off the most in the regions that you care about the most... i.e. when trying to avoid a High along an ocean sailing route or trying to evaluate a storm in any vessel or on land.

Also since the optimum factory adjustment to the units is mid range at sea level, if you are buying a unit for, say, Denver, then you could be off quite a bit on all pressures without a calibration.

 

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