Milk

CLR Calculator

Calculate the Corrected Lactometer Reading (CLR) from the observed lactometer reading and milk temperature. Essential for accurate SNF calculation.

CLR Calculator

Calculate Corrected Lactometer Reading (CLR) from observed lactometer reading and milk temperature.

°C
Standard reference temperature is 27°C
Formula
olr + ((temperature - 27) * 0.2)
olr Observed Lactometer Reading (OLR)
temperature Milk Temperature (°C)
Worked Example
1
Given:
olr = 27
temperature = 32
2
Apply the formula:
olr + ((temperature - 27) * 0.2)
3
Result:28

What is CLR (Corrected Lactometer Reading)?

The lactometer measures the density (specific gravity) of milk. However, the reading changes with temperature. CLR corrects the observed reading to the standard temperature of 27°C.

Temperature Correction Formula

CLR = OLR + [(Temperature − 27) × 0.2]

Where:

  • OLR = Observed Lactometer Reading at actual temperature
  • Temperature = Milk temperature in °C
  • 27°C = Standard reference temperature

How to Use a Lactometer

  1. Allow milk to reach room temperature (27°C ideally)
  2. Spin the lactometer gently in the milk cylinder
  3. Read the scale at the meniscus level
  4. Note the temperature of the milk
  5. Use this calculator to correct to 27°C

CLR Normal Range

Milk TypeNormal CLR Range
Cow Milk26–32
Buffalo Milk28–34
Mixed Milk26–33

Values below 20 may indicate adulteration with water.

Frequently Asked Questions

CLR (Corrected Lactometer Reading) is the lactometer reading corrected to a standard temperature of 27°C (80°F). It is used to estimate the specific gravity of milk and derive SNF content.

To measure CLR:

  1. Pour well-mixed milk into a lactometer cylinder
  2. Lower the lactometer gently and allow it to float
  3. Read the scale at the bottom of the meniscus
  4. Note the milk temperature
  5. Apply temperature correction: CLR = LR + 0.2 × (Temperature – 27°C)

Typical CLR values:

  • Cow milk: 26 – 32 (specific gravity 1.026 – 1.032)
  • Buffalo milk: 28 – 34 (higher SNF = higher density)
  • Watered milk: Below 26 (adulteration suspected)
  • Skim milk: Above 36 (fat removed increases density)

A CLR below 26 is a strong indicator of water adulteration and requires further testing.

Specific gravity = 1 + (CLR / 1000)

For example: CLR of 28 → Specific gravity = 1.028

Liquids expand when heated, reducing density. At higher temperatures, the lactometer sinks deeper (lower reading). The standard reference temperature is 27°C in India. Apply the correction: for every 1°C above 27°C, add 0.2 to the LR; for every 1°C below, subtract 0.2.
CLR helps detect water adulteration (CLR falls below 26) but cannot detect all types of adulteration. Starch, urea, detergents, and other adulterants require specific chemical tests (FSSAI rapid test kit). Always use CLR as a first screening tool, not as the sole adulteration test.
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