Electrical Conductivity Calculator

Calculate electrical conductivity of milk in mS/cm for mastitis detection and adulteration screening. Temperature-corrected to 25°C.

mS/cm
Conductivity reading from meter
°C
Sample temperature at time of measurement
Formula
measuredConductivity / (1 + 0.02 * (measurementTemp - 25))
measuredConductivity Measured Conductivity (mS/cm)
measurementTemp Measurement Temperature (°C)
Worked Example
1
Given:
measuredConductivity = 5.2
measurementTemp = 30
2
Apply the formula:
measuredConductivity / (1 + 0.02 * (measurementTemp - 25))
3
Result:4.71 mS/cm

Electrical Conductivity of Milk

Electrical conductivity of milk measures how well it conducts electricity, primarily due to dissolved ions (chloride, sodium, potassium). It is a rapid, non-destructive test used for:

  • Mastitis detection — Mastitic milk has higher conductivity (>6 mS/cm vs normal 4–5 mS/cm)
  • Adulteration screening — Added water or solids change conductivity
  • Process monitoring — CIP verification and heat treatment effects

Temperature Effect on Conductivity

Conductivity increases by approximately 2% per °C rise in temperature. Results must be corrected to the standard reference temperature of 25°C:

Conductivity at 25°C = Measured Conductivity / (1 + 0.02 × (Temperature − 25))

Conductivity Values for Normal and Abnormal Milk

Milk ConditionConductivity at 25°C
Normal Cow Milk4.0 – 5.5 mS/cm
Mastitic Milk> 6.0 mS/cm
Buffalo Milk4.5 – 5.2 mS/cm
Watered Milk< 4.0 mS/cm
Saline Added> 7.0 mS/cm

How Mastitis Affects Conductivity

In mastitis, the blood-milk barrier is compromised. Sodium and chloride ions from blood leak into milk, increasing conductivity significantly. A reading above 6 mS/cm at 25°C is a strong indicator of mastitis and warrants veterinary investigation.

Limitations

Conductivity alone is not sufficient for definitive mastitis diagnosis. Always confirm with:

  • Somatic cell count (SCC)
  • California Mastitis Test (CMT)
  • Clinical examination