The Simpson Model 228 is a special purpose AC/DC milliammeter that measures potentially hazardous leakage current on electrical and electronic equipment. This Instrument meets the guidelines published in IEC 990, “Methods of Measurement of Touch Current and Protective Conductor Current.” Most stadards agencies in the United States — including ANSI, ISA and UL are in the process of implementing the networks from IEC 990 into their specifications. The Model 228 tests equipment operating at 120-220 volts AC or DC power line circuits only. Instrument features include: • Separate leakage current networks for measuring the following electrical shock response levels: Perception/reaction (shock hazard) Let-go (shock hazard) Burn hazard • 0-300 volt scale for measuring open circuit voltage between accessible parts and ground. • An RMS reading meter with scales that read shock hazard up to 10 Measure- ment Indication Units (MIU), burn hazard up to 100 mA and peak indicating RMS shock hazard. (Refer to Section 7, Measurement Procedures) for more information. • Output connections for an external peak reading Instrument (required for measuring peak readings on non-sinusoidal waveforms). • Convenient battery test function. The 228 is battery operated. In some applications, the lead attached to the “Ground” input may not be attached to earth ground. As a result, the output jacks may be “floating.” To prevent a shock hazard, do not connect any connectors or equipment with accessible conductive surfaces.