Testing apparatus comprising an air pump 1 downstream of measuring equipment which measures a products characteristics. An induction 3 upstream of the measuring equipment, and an adaptor 4 connected at a first end upstream of the induction port 3, the adaptor 4 comprising a through bore 19 extending through the adaptor from the first end to a second end to receive an inhaler I. A lateral bore 20 is in communication with the through bore 19, whereby the air pump 1 in use draws air through the inhaler I and through the lateral bore 20. The adapter 4 is provided with a flow adjustment member 21 in the lateral bore 20. The member being adjustable to vary the flow through the lateral bore 20, and hence the relative proportions of air that are drawn in at the first end of the adaptor and the make up air drawn in through the lateral bore. The testing equipment may be one of an Anderson Cascade Impactor, Next generation Impactor, Particle Size Determination by laser diffraction or dose uniformity sampling apparatus.
