The Instek GDM-8255A benchtop digital multimeter (also called multitester) is a true RMS (root mean square), auto- and manual-ranging meter that measures voltage, current, resistance, frequency, and temperature, and performs continuity and diode tests in electrical applications. An audible continuity sensor confirms a circuit conducts electricity, and a diode test detects proper functioning of a circuit's diodes. The meter can also express AC and DC voltage in decibels (dB), the power ratio of decibels to milliwatts (dBm), and percent of the reading relative to a preset reference value. It also measures 2- and 4-wire resistance. The two-color VFD (vacuum fluorescent display) panel provides contrast and brightness for high-visibility in lab and workshop settings. The dual display allows two measurements to be displayed simultaneously. The meter displays the present measurement or the minimum (Min) and maximum (Max) reading in a session, for tracking sudden changes in readings. Relative mode displays the difference between the measuring value and the user-defined reference value. Relative mode is helpful when comparing two readings or removing test lead resistance from low-ohm measurements. A data hold function keeps a reading on the display for recording. The math mode manipulates readings according to the formula mx + b, where m and b are user-entered constants for scale factor and offset, respectively, and x is the actual reading as would be normally displayed. The meter has a compact profile with a stand that tilts the display up for easier reading or can be folded away to save room. The meter has RS-232C, USB, and digital I/O interfaces that export data to a computer.

This true RMS (root mean square) meter provides accurate readings when measuring linear loads, such as standard induction motors and incandescent lights, where the current or voltage has an undistorted waveform, or nonlinear loads, such as electronic devices or motors, where the current or voltage has a distorted waveform. AC + DC true RMS provides measurements taking into account the AC and DC waveforms. When turned on, the meter is in auto-ranging mode and automatically selects the correct operating range for the property being measured. It can be switched to manual-ranging mode, which allows the operator to choose the appropriate operating range. The LCD has a 200,000-count resolution, meaning it can display up to 199,999 units (5-1/2 digits) before the operating range needs to be changed. The meter meets International Electrotechnical Commission (IEC) safety standard Pollution Degree 2 for indoor use. The meter includes one pair of test leads, a USB cable, a calibration key (compatible with Fluke 5720A/5725A calibrators only), DMM-Viewer software, a 100-240V power cord, and instructions.

Specifications

H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.

Multimeters are electrical test meters that measure multiple properties of an electrical circuit, such as current, voltage, resistance, capacitance, and continuity. Available in handheld or benchtop models, multimeters diagnose electrical problems in electrical equipment, wiring, and power supplies. A variety of probes, clamps, and leads can be used to connect the meter to a circuit or device. Multimeters display information either in analog or digital form. Factors that influence meter choice include the electrical properties to be measured, the anticipated range of results, and the desired level of protection against transient voltage. Safety ratings are based on International Electrotechnical Commission (IEC) standards for low-voltage test equipment. IEC 61010 delineates four overvoltage installation categories. In general, a meter with a category IV rating will provide more protection against transient voltages than a meter with a lower category rating.

GW Instek manufactures test and measurement equipment such as oscilloscopes, spectrum analyzers, signal testers, and video surveillance systems. The company, founded in 1975 and headquartered in Taipei, Taiwan, meets International Organization for Standardization (ISO) standards 9002 and 14001.

What's in the Box?

• Instek GDM-8255A bench-top digital multimeter
• Test lead (GTL-117)
• USB cable (GTL-247)
• Calibration key (GDM-01)
• DMM-Viewer software
• Power cord
• Instructions