Process Sample Conditioning Systems

Process characteristics encompasses the pertinent physical characteristics of the process to be sampled and the sample to be conditioned. The major categories are gas, liquid or solid. Sample probes are a technology to themselves. Each application has characteristics which require design considerations for its sample probe. Heated sample transfer lines can utilize steam or electricity for the heat source. Steam leaks can be very dangerous to personnel and destructive to transfer lines and analytical equipment. Parallel-resistance constant-wattage heat trace cable can be rated for much higher temperatures than parallel-resistance self-regulating cables. Parallel-resistance power-limiting heaters are a major improvement over “zoned cable”. The manufacturers of power-limiting cable will spiral-wrap a positive temperature coefficient alloy resistor wire around a core fiber. Sample coolers can be air-powered or electric-powered. The function of these sample coolers is to remove moisture from the sample which is passing through them.