The Desco 19494 Portable Charged Plate Monitor (CPM) is a handheld meter designed to check the offset voltage and discharge times of air ionizers per ANSI/ESD SP3.3 and ESD TR53. The meter’s integrated timer measures decay rates from ±1000V to ±100V to determine the ionizers’ ability to neutralize both positive and negative electrostatic charges within the coverage area. The 180-degree rotary head with 2.75" x 1.25" plate allows the operator to read the display at various angles. The Portable Charged Plate Monitor is calibrated to NIST standards and includes a certificate.