Current Meter Maintenance Information and Resources
The AquaCalc is used with mechanical Current Meters like the USGS style Price AA and Pygmy current meters. These current meters most often use a contact switch to indicate a revolution of the cups. In modern current meters this is most likely a magnetic reed switch, but in older current meters this can be a small wire, often called a “cat whisker” that touches a rotating cam in the current meter switch head. AquaCalc also makes a Pygmy Digital Magnetic Head for the Pygmy current meter. This magnetic sensor uses a Hall Effect sensor, and is designed to work with AquaCalc.
The following picture shows a Price AA magnetic head current meter on a bridge crane for use in suspended measurements
Vertical Axis Current Meter Maintenance.
Some of these resources are old, but still good.
The USGS has instructions on current meter maintenance which can be found here: https://water.usgs.gov/osw/pubs/9906attachments.pdf
Office of Surface Water Information -- Publications (usgs.gov)
Other resources are available including this in depth video: https://www.youtube.com/watch?v=EINXEAHYsEI
The USGS has an educational site that discusses discharge measurement in broad terms here:
https://water.usgs.gov/edu/streamflow2.html
The USGS has more detailed training materials and a report on Discharge Measurements here:
https://pubs.usgs.gov/twri/twri3a8/html/pdf.html
(The whole report can be downloaded here:
https://pubs.usgs.gov/twri/twri3a8/pdf/TWRI_3-A8.pdf )
And finally the old “bible” of the USGS Water Supply Division: “Water Supply Papers 2175 - Measurement and Computation of Streamflow”. This has a lot of information and theory:
https://pubs.usgs.gov/wsp/wsp2175/
Need Accessories or Cables?
We have replacement parts and cables for the AquaCalc line of stream flow computers including the Digital Pygmy Magnetic Head retro fit your old Pygmy Current Meter with a new digital magnetic sensor.