The IEC standard calls forvolumetric infusion pump andvolumetric infusion controllerflow rates to be assessed overa 120 minute test period usingan intermediate flow rate of25 ml/min. The infusion is tobe delivered into a beaker andscale testing system.Sources of error in the testingsystem suggested by the IECstandard include:• Failure to zero the scale/balance with an empty, drybeaker.• Miscalculation of the volumeby weight (which is why thestandard suggests an electronic scale/balance whoseoutput is fed into a computerrunning the appropriate calculation to obtain the volumeby weight).• Loss of volume by evaporation(due to the length of the testing period). It should be notedthere is evidence in peerreview articles that evaporation is negligible under normal ambient conditions.There are, however, other testsystems besides the beaker andscale that will produce the sameaccurate results. For example,one can use a graduated buretteand stopwatch, or an infusion device analyzer (one thatincorporates and automates boththe graduated burette and thestopwatch functionality).As the name implies, a graduated cylinder or burette is acylindrical glass (or plastic) tubesealed at one end with a calibrated scale etched or markedon the outside wall. Graduatedcylinders come in a range ofsizes (volume capacities), andmuch like a measuring cup,volume is measured by adding liquid to the cylinder andcomparing the liquid level to thegraduated scale. The measuredvolume corresponds to the volume of liquid contained in thecylinder.It is very important to ensurethat one is looking directly levelwith the meniscus of the liquidin the burette to determinethe volume at the etched scalemarking (Fig. 5).It is also critical that the stopwatch be started at the exacttime the infusion pump beginsits delivery of liquid.Improper viewing of themeniscus or the need to interpolate between graduationmarkings, combined with anymismatch in timing between theinfusion device and the stopwatch will result in errors inmeasurement.The IDA-5 Infusion DeviceAnalyzer from Fluke Biomedicalsimplifies the process statedabove by integrating the burette“graduating” it with IR sensorsto measure the level of liquidinfused, and uses electronicstopwatch function technology, among many other featuresand functions in its design. It isbased on sophisticated measurement technology trusted bybiomedical professionals aroundthe world for over 20 years. TheIDA-5 is a full-featured devicethat measures instantaneousflow, average flow, occlusionpressure and dual flow based onIEC60601-2-24Measurements are continuously updated and stored so thatgraphs can be produced anddisplayed live to enhance theassessment of the performanceof the infusion device under test.