Enter the observed refractive index, sample temperature, and reference temperature into the calculator to determine the corrected refractive index.

Refractometer Temperature Correction Formula

The following formula is used to calculate the corrected refractive index:

nDc = nDo + CF * (T_sample - T_reference)

Variables:

  • nDc is the corrected refractive index
  • nDo is the observed refractive index
  • CF is the correction factor (typically 0.00045 for sucrose solutions)
  • T_sample is the sample temperature in degrees Celsius
  • T_reference is the reference temperature in degrees Celsius (usually 20°C)

To calculate the corrected refractive index, add the product of the correction factor and the difference between the sample and reference temperatures to the observed refractive index.

What is Refractometer Temperature Correction?

Refractometer temperature correction is the process of adjusting the refractive index measurement of a sample to account for temperature differences from a standard reference temperature. Since the refractive index of a liquid changes with temperature, it is important to correct for these variations to ensure accurate readings, especially when comparing to standard values or conducting precise quality control.

How to Calculate Corrected Refractive Index?

The following steps outline how to calculate the corrected refractive index:

  1. First, determine the observed refractive index (nDo) of the sample.
  2. Next, measure the sample temperature (T_sample) in degrees Celsius.
  3. Determine the reference temperature (T_reference) in degrees Celsius, which is typically 20°C.
  4. Use the correction factor (CF), which is typically 0.00045 for sucrose solutions.
  5. Apply the formula to calculate the corrected refractive index (nDc).
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Observed refractive index (nDo) = 1.3330

Sample temperature (T_sample) = 25°C

Reference temperature (T_reference) = 20°C