To get an accurate enthalpy chart, the clamps need to be placed in the correct locations. The high-temperature clamp should be placed right before the metering device (condenser side). The low-temperature clamp should be placed on a metal section of the suction line going to the compressor. Make sure it is not located next to something that would give off excessive heat like an exhaust manifold which might skew the readings. Adjust the location up or down away from the heat source.
