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How to Calibrate a Specific Gravity Controller

Specific gravity controllers determine the ratio between the densities of a sample substance and a reference solution. This reference solution is often water. However, some controllers use different solutions. Despite the actual reference fluid, water remains a baseline as its density is 1 kilogram per liter. Sensitive machines require regular calibration to ensure the accuracy of their results. Using two points yields far better calibration results than relying upon a single-point technique.

Things You'll Need

90 grams water
Flat-head screwdriver
10 grams sucrose

Instructions

- 1
  Cool the water to your specific gravity controller's recommended calibration temperature.
- 2
  Switch the controller into its low end calibration mode. Insert the controller's sensor into the water. Read the specific gravity. Determine how far it deviates from 1.0000.
- 3
  Adjust the controller's calibration screw with a flat screwdriver until the specific gravity is 1.0000.
- 4
  Remove the sensor from water. Clean the sensor.
- 5
  Prepare a 10 percent sugar solution by dissolving 10 grams of sucrose in 90 grams of water. Cool this solution to your controller's recommended calibration temperature.
- 6
  Switch the controller into its high end calibration mode. Insert the controller's sensor into the solution. Read the specific gravity to identify how far it deviates from 1.040.
- 7
  Adjust the controller's calibration screw with a flat head screwdriver until the specific gravity is 1.040.
- 8
  Remove the sensor from the solution. Clean the sensor. Prepare a new water solution and retest for accuracy.

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