GH5640 & GH5645 5 gallon Calibration
Elite Series Meter Calibration Guide
Read Before Starting: Calibrate using the same quantity you intend to meter regularly. In other words, if you are typically dispensing about 100 gallons, calibrate your meter using a batch of 100 gallons.
The factory calibration setting is 1.000.
To correctly calibrate the meter, use this formula:
New Calibration Setting = Current Calibration Setting × (Actual Gallons Pumped ÷ Gallons Shown on Meter)
1. Write down your current Calibration Setting
Before Beginning, hold Display for 5 seconds to open calibration menu, then WRITE DOWN the current calibration setting on the screen.
2. Start with a known amount of fluid
Dispense fluid through the meter into a container with clearly marked measurements or a known calibrated volume — such as a graduated 5-gallon container. The amount collected in the container is your ACTUAL volume dispensed. (Please note: Using a container with no marks may lead to an improperly calibrated meter.)
3: Write Down Meter Reading and Fluid Pumped
Example: Actual amount pumped = 5 gallons. Meter shows = 4 gallons.
4. Divide actual gallons by metered gallons
Example: 5 ÷ 4 = 1.25
5. Multiply that result by the current calibration setting
New Calibration Setting = Current Calibration Setting × (Actual Gallons Pumped ÷ Gallons Shown on Meter)
Example: If the meter is still at the factory setting: 1.000 × 1.25 = 1.25. Your new calibration setting becomes 1.250.
6. Repeat Calibration Process until Accuracy is Reached
Repeat the process until desired accuracy is achieved. Note: (It will be difficult to achieve high accuracy when metering small batches)
7. Ovoid Compounding Errors
If desired accuracy is not achieved after performing the calibration process 3 times, set meter to factory calibration setting (1.000) and repeat steps 1-6.
IMPORTANT:
Do NOT replace the old calibration number with only the new math result. You must multiply the result by the calibration setting already stored in the meter.
Simple Guideline
• If the meter reads too LOW, increase the calibration number.
• If the meter reads too HIGH, decrease the calibration number.
Always use this full formula:
Current Setting × (Actual Gallons ÷ Meter Gallons) = New Setting
Practice Example
Current setting: 1.190
Actual pumped: 5 gallons
Meter shows: 4.90 gallons
Formula:
1.190 × (5 ÷ 4.90) = 1.214
New calibration setting: 1.214
