New Cat IV Multimeters Offe high Accuracy, Superior Durabilty
By John O'Brien

If you asked 100 electricians to create the “perfect” multimeter for electrical measurement, there would undoubtedly be certain features each professional would incorporate into his or her design. These would likely include:

• Ease of use. Like all professionals, an electrician’s time is money. Whether in a residential or commercial application, tools that are easy to use lead to time savings, which subsequently translate to dollar savings. What’s more, ease of use helps reduce the frustration that accompanies more complicated instruments.
• Durability. Electricians find themselves in a variety of harsh environments, so the ability of a measurement tool to withstand severe conditions is crucial. Further, dropping instruments during the course of the workday – particularly when trying to reach areas that are not readily accessible – is unavoidable. Consequently, the instrument must be sufficiently sturdy to handle such abuse.
• Waterproof operation. There is a wide variety of high-moisture environments in which electrical measurements must be taken. The moisture may be due to the nature of a particular operation (i.e. a pharmaceutical or food processing facility), or simply due to high-humidity weather conditions. A quality multimeter has to be ready for both.
• High-voltage input protection. Severe damage can occur to a multimeter that is not built to measure high-voltage levels. Further, the lower the voltage the tool is equipped to accept, the less functional the tool becomes.
• Accuracy. Needless to say, accuracy is the most important function of any electrical measurement tool. Without it, the other qualities mean nothing.
• Favorable price point. The well-equipped electrician needs a large number of tools at his or her disposal. As a result, being able to save even a small amount of money on each instrument is a welcome benefit.

 

Extech, one of the world’s largest suppliers of test equipment, offers a new line of multimeters that incorporates those criteria. In fact, Extech’s 500 Series is designed specifically for professional electricians for use in heavy-duty, industrial applications across a wide range of industries.

Offered in three separate models, the EX510, EX520 and EX530, the new 500 Series can be used for any electrical application. For example, when testing the electrical service coming into a house or facility, Extech’s 500 series can be used to measure as low as 120 volts for a residential building or a higher voltage for a commercial facility. It can also be used for industrial engineers who need to accurately measure process signals and DC signals.

The durability of the 500 Series begins with the packaging of the product. It is housed in a double-molded case that is not only strong but extremely comfortable to grip, which contributes significantly to the product’s ease of use. Yet, despite the strength of the packaging, Extech has managed to keep the weight of the instrument down to a very low 12.3 ounces.

Electricians must often perform electrical measurement under severe and brutal weather conditions. Extech’s 500 Series can take measurements in the middle of an ice storm or in the heaviest downpour—without sacrificing accuracy. The rugged packaging is waterproof, making it perfectly suited for harsh, wet conditions. That allows it to be used effectively in any industrial process where there is a high volume of liquid present, such as wastewater or pharmaceutical applications.

In addition, its heavy-duty construction makes the 500 Series drop-proof up to a height of six feet. It also ensures that replacing the battery is virtually the only maintenance that will ever have to be performed. Extech’s faith in the resilience of the 500 Series is evidenced by the three-y ear warranty it placed on these devices.

Each of the models in the 500 Series features dual sensitivity frequency functions, large backlit LCD with bargraph, d iode open circuit voltage of 2.8V DC, Min/Max/Relative/Data Hold and double-molded test leads.

The 500 Series multimeters provides electrical input protection up to 1000 volts on all functions. This has resulted in a desirable, Category 4 (CAT IV) rating by the European-based International Electrotechnical Commission (IEC), one of the world’s most influential standards organizations dealing with electrical, electronic and related technologies. Recently, the 500 series received a seal of approval from Underwriters Laboratories (UL). One of the most recognizable and reputable providers of product certification in the United States, UL has been testing products for public safety for over a century.

The Model EX510 and EX520 offer displays counts of 6000, while the high-end EX530 offers an impressive 40,000, giving it sufficient resolution to measure low AC or DC signals. The EX520 provides t rue RMS, type K temperature (°F/°C switchable) and capacitance. In addition to those features, the EX530 also gives the user peak hold, duty cycle and 4 to 20 milliamp specifically geared toward the process engineer.

The temperature function of the EX520 and EX530 is especially convenient. This function allows the industrial user to measure the temperature of a specific process, between -58 degree F (50 degrees C) and 1382 degrees F (750 degrees C). For instance, if the user wants to measure the temperature of a motor, it can be quickly accomplished.

If a multimeter is not accurate, an electrician does not have much use for it. The 500 Series is extremely accurate, offering basic accuracy from 0.1 percent for the EX510 and EX520 models and up to .06 percent for the EX530. The importance of the accuracy provided by the four-digit EX510 and EX520 models, and the five-digit EX530, cannot be overstated. Suppose you have a two-digit voltmeter that reads 0 to 99 volts. Effectively it has a full-scale capability of 100 volts. But suppose you use the two-digit meter to measure a voltage with a value of 50.5 volts. What will the meter read? The only choices are 50 or 51, thus there will be an error either way.

There are competitive multimeters that will perform similar functions. However, few, if any, can perform them with the accuracy, toughness and input protection of Extech’s 500 Series.
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John O’Brien has been in the electronics industry all of his life. In 1962, O’Brien went into training for the Service and then worked for General Radio/GenRad for more than 23 years. Starting in bench repair, O’Brien worked his way up the engineering ranks with positions in field service and finally as product line manager. He joined Extech Instruments in 1995 and is currently manager of the technical support department.