Commercial Electric 1004 482 497

SaferProducts.gov consumer incident report 20231118-23915-2147343942. Severity: No Incident, No Injury. Product: Commercial Electric 1004 482 497 (3-Piece Technician Test Kit, package about 9-inches by 10 inches, green and gray . Part number on top right of package is 1004 482 497.). Incident: Before we get to what happened, I think you should know that I am a measurement expert. I am the chair of an [REDACTED] group that just revised [REDACTED], and I am chair of a group revising [REDACTED]. Now I want to report an unsafe measurement device that I came across by chance. It is the voltmeter part of a "3-Piece Technician Test Kit" sold by Home Depot, part number 1004 482 497. It is made by Commercial Electric. The problem is that the reading on the device was zero when there was actually a voltage on the circuit I was testing. The problem is not a fault in the instrument, it is a design error. Home Depot let me test a second sample, and the same problem was present. A voltmeter has two probes. When switched to measure AC, it should not matter which way round the probes are connected. With this device, it does matter if there is a DC component on the signal. In the case I was measuring. The reading was ZERO with the probes one way round, and not zero the other way round. I am aware that the condition of having some DC on an AC circuit is unusual, but that's what there was in my work. (I verified it with my oscilloscope.) If a user is unaware of the possibility of there being an AC potential even though the meter displays zero, that could be dangerous. The design error would not be evident in the absence of DC on the circuit, but the fact of a misleading indication could lead to an electric shock. (Frankly, I think Home Depot should pull the meter off the shelf until the design is fixed, but I cannot find a way to contact them that seems likely to achieve that outco