I am looking for ISO 7066-1-1989, Its basically for Assessment of uncertainty in calibration and use of flow measurement devices -Linear calibration relationships. Please share it if some one have. I will be thankful for this.
If you search on ISO number in internet, you may be able to download. It looked suspicious to me in requiring an exe file to convert to PDF, so I did not download. If you use standard meters, and calibrate and maintain them, you should be OK. The pygmy and Type AA meters have a spin test to check function, and you can send instrument back to company to get a recalibration, or repair, replacement if damaged beyond repair. I always carry mine to/from site in wood protective box, use top setting wading rod when appropriate, and be careful with it. Typically, you hope to be within 10% of the actual value. Perhaps the Doppler meters can do better. Flumes or weirs of specific calibrated design may be better for small streams.
@William
I tried to get it from Internet but unable to find it. Can you send link to me.
Another thing is that I am using salt dilution method for discharge measurement as it work fine for mountainous region.
http://www.freestd.us/soft2/837047.htm
I hope this link works.
If you have access to a fluorometer, constant injection of a known concentration and volume per time is a very effective approach.
A limited amount of salt may be acceptable for time of travel, high, low and mean velocity estimates which might be converted into a flow measure estimate. If you have a mean velocity, and cross section is fairly stable then the flow estimate should be pretty good. Unless you are injecting salt at a constant rate and concentration, and reach a leveling off of salt concentration downstream, the dilution method may not work
Equation C1 x R1 = C2 x R2.
C=concentration, R= constant flow rate, 1 is dye or salt at input at constant rate and 2 is downstream site peak leveled off with R2 the unknown flow rate.
If you are sticking with salt, a conductivity meter will help you decide when about 1/2 of salt has passed based on concentration per unit time . when 1/2 salt is passed, that should be mean velocity, so if 100 m downstream of input site and it takes 400 seconds for 1/2 salt to pass, then mean velocity for that circumstance is 0.25 m/sec if channel is fairly uniform. If the channel contains huge pools relative to flow rate, there could be some add issues to consider.
Stream cross section times mean velocity is discharge rate.
I am using salt dilution method for discharge measurement in small strems, too. Constant injection can do better method (versus single)
We used as reference measurement of the hydrometric propeller or doppler.
Our results were no more be within 10%
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