Temperature data about a solder machine is taken from three type "K" thermocouples (T/C) attached to the Coupon. Their purpose is to sense the impact of a solder machine setup on circuit board "like" material, as opposed to the RIDER pallet material.
The "Bottom Foil" T/C is inserted into the coupon as close to the bottom surface as possible without breaking through. The "Solder" T/C is exposed below the bottom surface of the coupon so it will contact the solder. The "Top Foil" T/C is inserted into the coupon near the top surface.