How Do I Calibrate a Hydrometer?

All hydrometers are factory calibrated at a set temperature. Consult the paper inside the hydrometer to see what temperature the scale is calibrated for.

How Can I Confirm Proper Calibration?

There are many ways to ensure hydrometer accuracy.

  1. Red Indicator Line
    Our GOLD Series Syrup Hydrometer and our 12″ 0-12 BRIX Sap Hydrometer come with a red line indicator which marks proper paper placement. That way, if the paper slips, you will have a way to know immediately. (All paper inserts are glued in place, but we do still see paper slippage from time to time.)
    Smoky Lake will stand behind its hydrometers and send a replacement if this occurs. Simply send a photo of the paper and its position compared to the red indicator line to Angela at We will send you a replacement.
  2. Vermont Certification
    Most of our hydrometers have the option to be upgraded with Vermont Certification. All of our approved Vermont Certified hydrometers are tested and stamped by the Vermont Department of Weights and Measures.
  3. Compare Readings to Alternate, Trusted Testing Devices
    • When comparing the reading of your hydrometer to an alternate hydrometer, be sure the hydrometers are both CLEAN.
    • Make sure to use the SAME sap sample for both tests.
    • Test a sample that is NOT steaming. Steam means that your sample is in rapid process of becoming more dense.
    • If the readings between your two different hydrometers do not correspond, then it would be mandatory to consult a third or fourth device to definitively rule out which of the first two methods was in error.
  4. Use a Compensation Chart OR Murphy Cup/Float
    When taking your hydrometer readings, remember that hydrometers are affected by temperature. For the most accurate readings, always test your sample’s temperature and use a compensation chart accordingly. Alternatively, when testing maple syrup, you can simplify that whole process by using either a Murphy Compensation Cup or Murphy Compensation Float to do all the compensation calculations for you. Actually, we at Smoky Lake NEVER use a syrup hydrometer without a Murphy Compensation Device. We feel that strongly about it.