The main difference is that the FROG™ may be used for soil, water or air sampling. The VOCAM™ may only be used for air sampling, and is primarily for distributed, fixed, or perimeter monitoring. The VOCAM™ has a heated PID to keep the PID lamp cleaner for longer periods of time. In addition, VOCAM™ has a regenerable hydrocarbon scrubber. System integrators will find the VOCAM™ to be a very compact robust solution for distributed sensing applications.