Everett, Wash.Need to measure AC line frequency in the field? How about insulation breakdown resistance? Voltage of non-sinusoidal waveforms? Test-and-measurement vendor Fluke Corp. is combining the capabilities of frequently used test tools into one compact new tool that can fill the bill for these disparate, yet related, measurements. Dubbed insulation multimeters, two versions are offered.
Fluke's Model 1587 Insulation Multimeter and 1577 Insulation Multimeter combine 1-kV digital insulation testers with true-RMS digital multimeters. These combo instruments are packaged as compact handheld devices that weigh one pound and fit in a toolbox or on a tool belt.
Both models also feature large display digits and a bright white backlight that works in low-light environments. These instruments can also be operated manually or as auto-ranging meters. They also include audible continuity beepers.
The rationale for these instruments is that the need for insulation testing in the field is increasing, yet conventional testers are large, bulky, and not easily carried. With the insulation multimeter, Fluke combines the most frequently-used features of an insulation tester and a DMM (digital multimeter).
This portable tool that can be carried into the field meets basic multimeter needs yet gives you an insulation tester that generates high voltage. That's suitable for testing motors, cables, and switchgear.
For its part, the 1587 provides insulation resistance testing up to 2-Gohms, using five output voltages ranging from 50-V to 1-kV. The 1577 tests up to 600-Mohms of resistance with either 500-V or 1-kV. Both meters are powered by four AA batteries, which provides enough power for about 1000 insulation tests.
A remote test probe enables one-handed insulation testing using a trigger on the probe handle. Significantly, insulation testing is disabled if the meters are connected to a live circuit of more than 30-V. What's more, following testing, the meters automatically discharge all capacitive voltage from the equipment under test to help prevent accidental shocks. That's a nifty feature, for sure.
The Insulation Multimeters also offer DMM functions, and more, as shown in this table for the two models.
In addition, the circuitry of the 1587 is capable of accurately measuring voltage and frequency on variable-frequency motor-drive systems, using a lowpass filter that blocks frequencies above 800-Hz. Such systems are increasingly common, but create electrical noise that sometimes baffles ordinary DMMs.
These multimeters also carry 600-V CAT IV and 1000-V CAT III safety ratings. In fact, they're engineered to withstand voltage spikes of 8-kV.
For those of you not familiar with CAT ratings, the IEC (International Electrotechnical Commission) standard 61010 defines four measurement categories (CAT I to IV) based on the magnitude of danger from transient impulses. CAT III meters are designed to protect against transients in fixed equipment installations at the distribution level. CAT IV meters are designed to protect against transients from the primary supply level (overhead or underground utility service).
The meters come with test leads and probes, alligator clips, a K-type thermocouple (only on the 1587), and a remote test probe. These items are enclosed in a hard case.
The meters' impact absorbing yellow boot also accepts Fluke's TPAK magnetic hanging system. That provides for hands-free operation.
Both models also carry a three year warranty. Price for the Fluke 1587 Insulation Multimeter is about $550. The Model 1577 costs about $450.
Click here to download a datasheet (in Adobe Acrobat .PDF format).
For more information contact Fluke Corp., PO Box 9090, Everett, Wash. 98206. Phone: (888) 308-5277. Fax: (425) 446-5116. E-mail: email@example.com
Fluke, 888-308-5277, www.fluke.com