The Desco 98221 Wave Distortion Monitor Verification Tester is used to perform periodic test limit verification of Desco Wave Distortion Monitors. Verification may be accomplished without removing the monitor from its workstation. The Wave Distortion Monitor Verification Tester is National Institute of Standards and Technology (NIST) traceable. Frequency of verification is based on the critical nature of the ESD susceptible items handled. Desco recommends annual calibration of workstation monitors and the Wave Distortion Monitor Verification Tester.