Beckmans Digital Multimeter

tested by Richard Perez, Chris Greacen, and Mark Newell

The digital multimeter (DMM) is our eyes into the invisible world of electricity — without it we're flying blind. The DMM is the measurement and troubleshooting tool for home power producers. The new Beckman 2020 is a true rms reading DMM with all the features, including data recording, of instruments costing much more.

Beckman 2020 DMM functions and specs

This instrument reads true rms voltages and currents. This means that the Beckman 2020 will accurately measure both voltage and current output from inverters. The 2020 will measure ac voltage, ac current, DC voltage, DC current, frequency, duty cycle, capacitance, and resistance. This DMM also is outfitted for diode and transistor testing. The instrument will record maximum, minimum, maximum minus minimum, and average data. It will make positive and negative peak voltage measurements on all types of ac waveforms. Basic DC accuracy is rated at 0.02%, while ac accuracy is 2.0%.

The 2020 is an autoranging meter that only requires the user to select the desired function. The meter will then automatically select the proper range. The 2020 is equipped with a bar graph meter in addition to numerical readout. The 2020's liquid crystal display (LCD) has a very readable red backlight for operation in the dark. The display is equipped with annunciators for every conceivable function, from low battery warning, to the presence of dangerous voltage; it's all there on the display.

The Beckman 2020 is 7.5 inches (175 mm) tall by 3.5 inches (90 mm) wide by 1.3 inches (34 mm) deep. It weighs 20 ounces (568 grams). The 2020 is housed in a protective rubber-armoured case with flip-out stand and hang-up strap. The 2020 uses a standard 9 Volt (MN1604) transistor radio battery as a power source. Battery life is about 200 hours or less if you use the backlight often.

Using the Beckman 2020

We have been using three different Beckman 2020s. We are a beta test site for Beckman and evaluated their prototypes before testing their final production version for this article. Participation in this process has led us to really give the 2020 a full workout in a wide variety of situations.

The 2020 is very simple to use. Just select the function and the instrument does the rest. Once we were acquainted to the menu style operation of the 2020, accessing the various special functions, such as recording, was simple. The 2020 has standardized jacks on its front. All of our accessory probes (like temperature and clamp-on current probes) plugged into and ran on the 2020 with no problems.

Beckman 2020 performance

When it comes to instrumentation there are really two distinct criteria — function and accuracy. First an instrument must be able to perform a measurement. Then it must perform this measurement accurately. The function criteria comes first. For example, if a DMM does not read true rms voltage and current, then it cannot measure a modified sine wave inverter's output accurately regardless of its accuracy when measuring a sine wave.

It is inevitable that the Beckman 2020 will be compared with the Fluke 87 DMM. Fluke was first on the scene with these functions in an affordable DMM. In evaluating the performance of the Beckman 2020, we compared its functionality and measurements to those of three different Fluke 87 meters. Here is what we found.

The Beckman 2020 has several functions and capabilities that the Fluke 87 does not. For example, in record mode, the 2020 computes the maximum minus minimum value

Things that Work!

and stores it. The Fluke 87 does not have this function. The 2020 will automatically select 4 1/2 digit mode and maintain its 100 millisecond sample time in this mode. The Fluke 87 must have its 4 1/2 digit mode selected manually and its sample time drops to 1 second — ten times slower than the 2020. While this may seem trivial, it has greatly aided us in making measurements across shunts. Here very small DC voltages are present and the extra resolution and speed are pronounced. The data record function on the Fluke 87 runs for 36 hours then stops. The data record functions on the Beckman 2020 run until the battery is depleted, about 200 hours. The mechanics of running the 2020 are solid and reliable. The display is much larger and easier to read than the Flukes. The 2020's red backlight gives much better display illumination than the backlight in the Fluke.

In terms of accuracy, none of the three Flukes agree with either each other or the Beckman 2020. The differences in measurement between all these DMMs is trivial. When you reach accuracy levels of a fraction of a percent, it is impossible to tell who is more correct without calling in the National Bureau of Standards. The Beckman 2020 is

plenty accurate enough for any type of home power measurements or troubleshooting, even on the professional level. The only radical disagreement between our Flukes and the 2020 was when making frequency measurements on very noisy power sources like alternators and LCBs. Here the Fluke was better able to dig out accurate data from a sea of noise.

The Beckman 2020 has a list price of $249.00 and the Fluke 87 has a list price of $325.00. Both carry a three year warranty.

Conclusions

The Beckman 2020 is a true rms reading DMM with high accuracy at a low price. It offers more features and faster speed with more resolution than instruments costing more. Now if could only make espresso...

Access

Authors: c/o Home Power, POB 520, Ashland, OR 97520 • 916-475-3179

Makers: Beckman Industrial Corp., 3883 Ruffin Road, San Diego, CA 92123 • Outside CA 800-854-2708 • Inside CA 800-227-9781 _

ENERGIA SOLAR ~ SOLAR ENERGY

Solar Power

Solar Power

Start Saving On Your Electricity Bills Using The Power of the Sun And Other Natural Resources!

Get My Free Ebook


Post a comment