Knowing the specific contaminant and exposure levels is important to determine the appropriate respirator and cartridge for your work environment. This information will also help in estimating the life of selected 3M™ Cartridges. 3M™ Organic Vapor High Sampling Rate Monitor 3501+ uses diffusion, rather than a pump, to collect an air sample with an accuracy of +/-25%, at a 95% confidence level for many workplace organic vapors, for both personal or area sampling. It contains 562 sampling ports to generate high sampling rates and is designed to detect organic vapors at low concentrations or during short-term (STEL) sampling when low detection limits are important. Because of the high sampling rate, this monitor may exceed capacity at high concentrations or during long sampling times. After following all instructions, send the monitor to be analyzed in the lab of your choice. This monitor has a 2-year shelf life from its production date.