How does the Cal Number work?
For Raven systems, the cal number = the number of pulses your flow meter produces when 10 gallons pass through it. The controller counts pulses, then divides by your cal number to display gallons.
Reading too LOW? (Under-applying)
If the console shows less than you actually applied, you need to DECREASE the cal number. Dividing by a smaller number produces a larger result — making the display count up faster.
Reading too HIGH? (Over-applying)
If the console shows more than you actually applied, INCREASE the cal number. This makes the display count more slowly to match reality.
Does carrier type affect the cal?
A turbine-style flow meter measures volume regardless of what's flowing through it — a gallon of 28% fertilizer takes up the same space as a gallon of water. Generally you do NOT need to re-calibrate when switching products. However, slight differences in viscosity can cause minor variation — use this tool to fine-tune after a field test if needed.
Catch Test (If Tag is Missing/Unreadable)
1. Set the meter cal to 10 in the console.
2. Set total volume to 0.
3. Run exactly 10 gallons through the system into a container.
4. The new total volume reading on the console IS your new meter cal number.
Troubleshooting Inaccurate Readings
Check the turbine for debris or buildup. Ensure the sensor is tight against the meter body. Use a jumper wire to test wiring if needed. Air in the lines can also cause erratic readings — bleed the system before calibrating.
NH3 Specific
The tag number on an NH3 meter is in gallons. To convert to pounds of Nitrogen, divide by 4.22 (e.g., if your cal produces 100 gal, that's approximately 82 lbs N since NH3 is ~82% N by weight and the conversion factor accounts for liquid density).
Using a Raven flow meter with a non-Raven system?
Raven cal numbers are based on 10 gallons, not 1 gallon. If using a Raven meter with an Ag Leader or other brand, divide the Raven cal by 10. If using a non-Raven meter with a Raven console, multiply that meter's cal by 10.
