<title> <META NAME="description" CONTENT="AquaCalc LLC / JBS Instruments specializes in stream flow measurement devices like the AquaCalc that are used in the field of hydrology."> <META NAME="keywords" CONTENT="jbs instruments aquacalc aquacount stream flow measurement water discharge current meter hydrology usgs"> </title>

This page contains some of the most common questions we get at AquaCalc. Please feel free to contact us with your own.

This page last updated July 18, 2001


Q. How can I get a manual for the AquaCalc Pro?

Using meters

Measuring Problems


Q: How do I use the new Standard Rating Table No. 2 for AA and pygmy Current Meters with my AquaCalc?

Please click here to go to a special discussion of the new Standard Rating Tables for the Price AA and pygmy current meters.

Q: Why does the Basic version of the AquaCalc 5000 firmware have four user-defined / non-standard meter constants instead of five?

The Basic version of the AquaCalc 5000 firmware has a problem with two line segment meter rating curves.  The intercept value (the fifth constant) is a fixed value of 2.2 and cannot be changed by the user. This two-segment feature was originally intended to be used only with ice-meters having a two-segment curve and a cross-over of 2.2. Please see the revised Basic firmware instructions for Using Non-Standard / User-Defined Meters for more information. You may contact Customer Support for information on an upgrade that will fix this problem.

Q: What meters can I use with the AquaCalc?

In addition to AquaCalc’s Digital Magnetic Head for the Pygmy current meter, all meters that have mechanical or optical switches. This includes

While many of the standard meter's rating curves are  built in to the AquaCalc, you can always add custom meter rating curves as additional meters.

Q: How can I tell which firmware version I have in my AquaCalc?

The firmware version of your AquaCalc is displayed in the opening screens when the AquaCalc is first turned on. Please click here for more information and examples.

Q: Why can’t I make a velocity measurement?  I can hear the signal using my headphones.

A: Check and test the AquaCalc’s meter cable connections. Are you trying to take a measurement in Station 1 position?  The AquaCalc does not permit making a velocity measurement in Station 1.

Make sure that your measurement time is greater than zero. Very short measurement times (those less than 3 seconds) may measure so quickly that you can not see the display change.

Q: Will I lose my transect records when I replace the 9 volt battery?

A: No.  As long as the 3 volt lithium backup battery is good, you will not lose stored data when you remove the 9 volt battery.

Q: How often do I need to replace the batteries?

A: The AquaCalc 5000 uses 2 batteries: A 9-volt, and a backup battery.  The AquaCalc Pro uses two 9V batteries. The 9 volt batteries should be replaced soon after the “low battery” message appears in the display.  This message first appears when voltage in the battery has dropped to roughly 6.5 volts. The 3-volt lithium backup battery (coin cell) in the AquaCalc 5000 should be checked once a year.  It needs to be replaced only if it tests less than 3 volts.  Important:  AquaCalc’s transect and measurement information stored in memory  will be lost when removing the 3-volt backup battery, unless a good 9-volt battery is installed and the unit is turned on before the backup-battery (coin cell) is removed!

Q: Why does AquaCalc reset the timer and counter during a measurement?

There are two primary reasons:

  1. The cat whisker hairs are dirty. When using a cat whisker be sure that the cat whisker is adjusted properly and free of oil and dirt. The proper adjustment of the cat whisker allows contact to be made through 30 degrees of rotation (dwell).
  2. You are in a turbulent flow condition. If the above doesn’t fix the problem, you may be trying to measure in a surging stream condition. If the AquaCalc sees rapid changes in the velocity of the stream that exceed 50% of the previous cup rotation, it will reset itself in order to get a stable measurement. Move left or right to a new vertical distance and measure again. This problem is more common with the Pygmy meter.

For more information on AquaCalc resetting problems
click here.

If you frequently perform measurements in turbulent flow conditions, you should consider updating your firmware EPROM to the latest version which has greatly improved turbulent flow handling capabilities.

Q: Why won’t my AquaCalc count when connected to an A of B reel, when I can hear the clicks with my headphones?

Your slip rings or brushes may be dirty. Clean the slip ring and carbon contact on the reel.

Q: What is the difference between the AquaCalc 5000 Advanced (Professional Series) and the Basic series of firmware.

The Advanced firmware (formerly know as the Professional Series) includes additional features not found in the Basic Series. Some of these include:

In addition, the Advanced (version H) firmware includes many additional features requested by the USGS’s HIF program, designed to ensure the accuracy and integrity of measurements. This version produces warning flags both on the display and in the output that identify if the wrong meter, suspension weight, or measurement was used for the stream conditions based on USGS measurement techniques guidelines.

Q: How does a station as defined in the AquaCalc 5000 differ from a traditional station?

The word “station” has a slightly different meaning when using an AquaCalc 5000 than you may be used to. A traditional “station” (vertical) is a position in a stream cross-section identified by a distance.  Several measurements (observations) can be made at different depths at that same distance. 

In the AquaCalc 5000, a station is the same as an observation. So, in the AquaCalc you can have two “stations”, each at a different depth, but both at the same distance. In the AquaCalc 5000, a station is an individual measurement (observation) at a given distance and depth. Two measurements (0.2 and a 0.6) taken at a given distance are both defined as stations.

Q: Why can’t I perform a measurement in the first station in an AquaCalc 5000?

To account for the Edge of Water, the AquaCalc 5000 will not measure at the first or the last vertical locations. This helps to define the edge-of water correctly.

Q: Why do I have a “CORRUPTED MEMORY” warning?

The most likely sources for this warning are:

See the Trouble-shooting section of your manual for more details, or contact Support.


Frequently Asked Questions

AquaCalc LLC. telephone +1.916.372.0534 e-mail: sales@aquacalc.com