The physical properties described below are tested on antifreeze solutions sent to Dyne Fire Protection Labs. The physical properties are not a measurement of performance and as such will not cause the sample to FAIL. If the value is outside of the specification, it is simply noted as OUT OF SPEC.
|Physical Property Test Type||Definition||Possible Reasons Why Value is Out of Spec|
|Appearance||Appearance is the description of the color, consistency and the visible presence of sediment or particles.||
The appearance can indicate the type of antifreeze.
The appearance is often OUT OF SPEC and can indicate several things such as:
|Refractive Index||The refractive index is a measurement of the angle in which light bends as it passes through the sample.||
The refractive index is proportional to the amount of antifreeze in the sample and will increase as the concentration of antifreeze increases.
Please note the refractive index of tap water is approximately 1.3330 at 20 degrees Centigrade.
|Density (Specific Gravity)||The density is a measurement of the weight of a specified volume and is reported in grams per milliliter. Some labs report this as specific gravity, which is the relative density compared to water.||
The density is proportional to the amount of antifreeze in the sample and will increase as the concentration of antifreeze increases.
Please note the density of tap water is approximately 0.998 grams/milliliter at 20 degrees Centigrade.
|pH||The pH value determines the acidity/basicity (ion activity) of the sample.||
The acceptable pH range limits are 6.0-9.5:
The type and concentration of the antifreeze solution is the only property which can fail. It is the responsibility of the system owner to ensure the freeze point of the antifreeze solution is low enough to remain a liquid under all the anticipated environmental conditions.
|Performance Test Type||Definition|
|Estimated Concentration by Weight and by Volume||
The type of antifreeze solution and the concentration - by volume and weight - is determined by the physical properties of the solution in addition to the freeze point verification test. The acceptable concentration of the various antifreeze materials is determined by the National Fire Protection Standard 25, 2014 Edition - Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems:
|Estimated Freeze Point in Degrees Celsius and Degrees Fahrenheit||
The estimated freeze point in degrees Centigrade and degrees Fahrenheit indicates the temperature at which the solution will begin to freeze. It is not recommended that systems be exposed to temperatures below this freezing point for any extended time period.
|Freeze Point Verification||
The estimated freeze point of the antifreeze solution is verified by placing a sample of the antifreeze solution into a freezer.