Cleveland-Kidder® Intrinsically-Safe Barrier Blocks permit the use of UL Listed Cleveland-Kidder Tension Transducers in hazardous Class 1, Group A, B, C, or D atmospheres, when combined with CMC Tensi-Master Indicators, DIN Rail Amplifiers, and Controllers. The Transducers may be installed in the hazardous area, without purging, up to 150 feet away from the Barrier Blocks, and the Indicator or Controller when located in a non-hazardous area and connected in accordance with CMC Control Drawing A800-42273 or A800-42281.