Accuracy
EGT Accuracy
The Entrained Gas Tester delivers reliable, repeatable measurements of air content in liquid solutions. The EGT's measurement principle is based on Boyle's Law (P1×V1 = P2×V2), a well-established physical law that provides a consistent and accurate basis for determining entrained gas percentages.
By applying exactly one atmosphere of pressure to the sample and observing the compression of the trapped air bubble in the Pressure Indicator, the operator can determine the precise moment at which the correct pressure has been reached. This ensures consistent results across repeated measurements and between different operators.
The simple counting method — tracking full revolutions of the knob after pressure is applied, then applying the Correction Factor and Percentage of Air Factor — minimizes operator error and produces results that are both accurate and easy to verify.
How the Measurement Works
Fill the Sample Chamber
Fill the EGT tube with approximately 1½ pints (700 ml) of the liquid sample.
Apply One Atmosphere
Turn the knob to apply ~15 psi pressure. Watch the Pressure Indicator bubble reduce to half its size.
Count Revolutions
Release pressure by turning the knob back out, counting the full revolutions until fully released.
Calculate Percent Air
Subtract the Correction Factor, then multiply by the Percentage of Air Factor to get the final result.
EGT — Accuracy Reference Chart
P₁ × V₁ = P₂ × V₂
Boyle's Law — the physical principle behind every EGT measurement