Some of you may ask why is the thermal expansion of water important. All
glassware is calibrated to measure liquid at 20C, however we are testing
liquid at 37C. How do we measure out preheated media. Easy. Just remember
that the density of aqueous media is known from 20C to 37C, so we can
calculate the change in volume for the same mass of water. The density of
water at 20C is 0.99823 g/ml. At 37C it is 0.99370 g/ml. The expansion is a
factor of 1.0046 or 0.5 percent. In other words the same mass of water will
take up 0.5% more volume at 37C. 1000 ml of media will be 1005 ml at 37C,
500ml will be 502.5 ml.