Since 1975, ROOTS® Vapor Recover Meters have set the standard for California Air Resources Board (CARB) approved Gas Volume Meters. The ROOTS VRM is designed for, tested and approved by CARB. As Air Resources Board specifications change, we quickly respond with product enhancements to maintain our approval to Executive Order G-070, Source Test Procedure ST-39 – Regulation 8-7-302, and other associated Test Procedures such as TP-201.1, TP-201.1A, TP-201.2, TP-201.3, TP-205 and TP-201.5. Our 8C175 ROOTS® PX has a non-compensated, high frequency pulse transmitter using Solid State construction to eliminate mechanical switches for maximum reliability and minimized maintenance. A mechanical odometer is not included. The meter maximum base rated capacity is 800 CFH. The 3M175 ROOTS® Vapor Recovery Meter has a direct reading odometer-type index with minimum increments of 0.02 cubic feet for minimum readability of 0.01 cubic feet. Precision is ±2 percent of the gas volume reading, or better. It is available with a low frequency (TPWS) or high frequency pulse output (CEX). The meter maximum base rated capacity is 3,000 CFH.