Sensitometer exposure is different after service

Why does a sensitometer expose differently after being serviced?Exposures Are Different After Repair or Recertification

When an X-Rite sensitometer is repaired or recertified (factory calibrated), it will be adjusted to expose as close to the X-Rite masters of that same model.  These master models are factory maintained to strict standards.  X-Rite Service Technicians are able to fine tune the exposure settings to allow both the master and the customer's to expose closely to each other.  Because of this, the customer's instrument may expose slightly different when it is returned. 

Typically, the user will be able to minimize that difference by ensuring that the DIP switches are set the same as they were set before servicing but will need to do a crossover or 5 day average to create new aims.