An apparatus and methods for measuring the clamping force applied to a substrate by clamping elements of a substrate holder. The apparatus include a pneumatic cylinder, a two position, three way valve and a pressure gauge. In a first position of the valve, the gauge and a bore of the cylinder are vented or pre-pressurized. In a second position of the valve, the bore and gauge are isolated. The methods include placing the apparatus with the valve in the first position between clamping elements set to a non-clamping position, moving the valve to the second position, setting the clamping elements to a clamping position and reading a pressure on the gauge.