he Apex Instruments Standard Method 17 and 201A Heated Probe for sampling particulate matter. Multiple fitting arrangements and filter assemblies are available with an in-stack filter. Features a 1” diameter sheath constructed from corrosion resistant stainless steel, modular offset 3/8” pitot tip, 1/4” stainless steel quick connects, Type-K thermocouples for stack & probe temperature, probe heater, orsat line, and small parts package. Standard lengths are 3’ to 16’. Longer lengths and custom orders are available by request. Probes are ordered according to nominal (liner length). Effective length is one foot less than nominal length.