Mass Balance and Volume Compare mass, balance and volume calibration services by matching the current scope, range, method, uncertainty, certificate and service location to the equipment's intended use. Choosing a calibration provider sounds simple until the quotes arrive. One laboratory offers mass calibration. Another lists balance calibration. A third provides volume calibration using a gravimetric method which, confusingly, also involves a balance and reference weights. The prices, stated uncertainties and certificate formats may differ just as much as the services themselves. These services are related, but they don't calibrate the same measurand or solve the same problem. Mass calibration assigns values to weights and mass standards. Balance calibration evaluates the performance of a weighing instrument. Volume calibration determines how much liquid a vessel or device contains or delivers under defined conditions. Effective calibration service selection starts by id...