Thermometers and Hydrometers may need to be recalibrated. Does yours?
Properly calibrated instruments are required to adhere to laboratory SOP’s. Shock, contamination and other factors can cause drift from accepted values. In general laboratory use, it is recommended that you recalibrate liquid in glass thermometers at one year intervals. NIST further recommends six month intervals for liquid in glass thermometers used as standards. Other factors to consider in determining recalibration intervals include SOP’s, calibration history, measurement assurance data, data for the population of similar equipment, and statistical analysis methods. This would apply to hydrometers as well.
NIST Publication GMP-11, Good Measurement Practice for Assignment and Adjustment of Calibration Intervals for Laboratory Standards, establishes calibration intervals for standards and instrumentation used in measurement processes. NIST guidance documents are available on their website.
* For calibration points between 0 and 100°C. Points outside that range can take up to 10 days. Stated turnaround is time from receipt of your instrument and complete work order.