The sub-committee responsible for ASTM C110, Standard Test Methods for Physical Testing of Quicklime, Hydrated Lime and Limestone, is asking you for your help in an upcoming Interlaboratory study (ILS) on gas pycnometry (helium). Currently, the specific gravity of hydrated lime products (ASTM C110 Section 21) uses a liquid displacement apparatus (Le Chatelier Flask and ethyl alcohol) for this determination. As an alternative method, the sub-committee is exploring helium gas pycnometry. Toward this end, main committee C07 (lime) has authorized the sub-committee to register an ILS with ASTM (ILS #238) for the purpose of establishing precision and bias values for gas pycnometry in the determination of the density of hydrated lime. Based on the results of this study, gas pycnometry may be balloted as an alternative test method for determining material density within C110.

To date, we have recruited 6 labs to participate in the ILS and we appreciate their willingness to participate! We would like to add participants to this pool and we need your help to do so. If you have, or know of a colleague that has, a helium gas pycnometer, please send their contact information to me so that I might ask them to participate. The work load for this ILS will not be overly burdensome, and will only require 9 individual sample runs (3 replicates each of a High Calcium Hydrated Lime, Type S Hydrated Lime and Type N Hydrated Lime). Samples are being collected for distribution to participating labs in March/April of 2008. Labs will have approximately 3 weeks upon sample receipt to submit their results.

If you have not yet participated in an ASTM ILS study, this is a good opportunity to learn about organizing such work and opportunities to expand your network of colleagues that have and use helium gas pycnometers. If you can help, please pass on your contact information by Thursday, January 31st 2008. ■