Handheld multimeters: Innovative yet affordable

The Indian test and measurement (T&M) market has been fairly resilient and is growing steadily. Rapid technological developments have resulted in a need for accurate data, and instrumentation plays a very decisive role in everyday science. Large companies are vying for the attention of the T&M community, bringing a growing array of technologies to the field worker’s shirt pocket—handheld multimeters being one of them.

By Richa Chakravarty

Tuesday, February 01, 2011: A multimeter is an instrument that finds diverse use across different industries/sectors. Traditionally, multimeters have been treated as devices that can measure the basic electrical parameters—voltage and current, apart from related parameters like resistance, continuity, etc. Analogue and digital multimeters (DMMs) are the two types available in the market. Having limited use, analogue multimeters have less demand. However, developments in sectors like infrastructure, IT parks, power and education show a great opportunity for growth in the DMM market as servicing, repairing and installing complex equipment requires diagnostic tools that provide accurate information. DMM being available in handheld and bench top variants has found application in different verticals.

Enormous growth has been seen in the multimeter market in India over recent with a good balance between demand and supply. About 25 per cent growth rate has been witnessed by this sector.

“There has been an increasing demand for application specific, sophisticated multimeters catering to the semiconductor, communication and military sectors. The highly accurate, programmable multimeters meet the challenges of faster electronic systems, replacing their mechanical counterparts in the automotive, pharmaceutical and process control industries,” says Naresh Narasimhan, country marketing manager, Tektronix India Pvt Ltd. The company is a leading supplier and manufacturer of test instrumentation for engineers focused on electronics design, manufacturing and advanced technology development.

“The present trend is that end users expect increased functionalities in instruments at lower prices. The Asia Pacific region is a very important market for multimeters with the maximum demand from China and India. End users, especially in this region, are highly cost conscious, and hence, want the best price value. The decreasing prices of components have helped lower the cost of manufacturing but manufacturers need to look into reducing test expenses so as to bring these in line with a lower product price,” explains Sadaf Arif Siddiqui, senior technical marketing engineer, Agilent Technologies India Pvt Ltd. The company is a leading US based manufacturer of T&M equipment.

Innovation—the key to success

Engineers and manufacturers constantly want the best equipment, whether it is for compliance testing, communication testing solutions, machine vision and inspection, and so on. This has led the T&M industry to the development of instruments that are not only precise but also incorporate the latest trends and features. And handheld meters are no exception to this trend. With the advances in technology, one can get high end, modern handheld multimeters with the best performance and reliability at affordable prices.

Handheld multimeters are generally used in harsh field environments. These portable meters can withstand high and low temperatures, dusty and wet atmospheric conditions, besides shock and vibration. Apart from regular functions like component testing, troubleshooting, routine maintenance of electronic and electrical systems, and components repair, these handheld multimeters today are available with a number of innovative features. A printer interface, data log/storage, better display technology, connectivity to computers through recommended standard RS232/universal serial bus (USB) for the storage of data and analysis, are few such features.

“The next advancement in handheld multimeters is towards more graphical screens, coloured displays, offline storage memory, Wi-Fi connectivity, visual and audible continuity indication, IP-54 certification (water and dust resistance), category III/IV safety protection, etc,” explains Chandmal Goliya, director, Kusam Electrical Industries Ltd. This Mumbai based company is a supplier of leading brands in the T&M space.

“While compact digital multimeters give all the essential features in a compact and easy-to-use tool, general purpose multimeters are rugged devices for everyday use. Whether you need a wireless display to make your job easier or a built-in temperature feature, these meters give an accurate reading for electrical maintenance and troubleshooting,” explains Suneel Kapoor, national manager (IG-India), Fluke South East Asia Pte Ltd. Fluke Corporation is one of the world leaders in the manufacture, distribution and servicing of electronic test tools and software.

These multimeters are used in industrial electronics (including consumer electronics), academia, aerospace/defence, process industry, automation, automotive industry, the electrical industry, R&D houses, etc. The market has a range of multimeter offerings which come in various form factors namely—USB modular, PXI (PCI extensions for instruments) modular, clamp type and organic light emitting diode (OLED) handheld multimeters.

“Further additions to the booty are not only cost effective but feature rich multimeters which include DMMs with the variable frequency drive (VFD) measurement function, inbuilt scope graphs in handheld multimeters with USB connectivity, multimeters with remote indications, infrared thermometers, very high frequency response DMMs at affordable prices, etc,” says Manish Kwatra, managing director, Metro Electronic Products, a company that imports and distributes Mastech multimeters and Metro Q test equipment.

One of the latest features being added to handheld multimeters is ‘trend capture’. It is a trend plot style graphical representation of a logged session which has been recorded by the meter. This display can be viewed right on the meter as soon as the recording session is completed. For a troubleshooter on the go, the benefits can be huge. “The user immediately view recorded results from a logging session, which could have been up to 200 hours long, allowing for an instant analysis of any unusual events without the need of a PC. Multiple recording sessions can also be completed and viewed right on the meter without the need for a download. In addition to being able to view the trend information right on the screen, a cursor is also available to highlight a specific event (including event details). You can also zoom in for a closer look at the data,” explains Suneel Kapoor.

Other features added to DMMs are a thermometer and a push button low pass filter that can accurately measure adjustable speed motor drives. The clamp type multimeter protects technicians from the high current levels by measuring the current inductively and eliminating the risk of a debilitating shock through the opening of the circuit. Insulation multimeters combine the feature of an insulation tester and a DMM in a lightweight tool that fits in the hand. Now, electricians and technicians have a portable tool that they can easily carry into the field – and it meets their basic multimeter needs while giving them an insulation tester that generates up to 1kV.

Latest products in the market

The latest multimeters gained a sizeable market share very early because of their various benefits. “These meters are ideal for all types of temperature testing. They are useful in different industries. Available in different shapes and sizes, depending upon usage and utility, these are highly accurate and can withstand rugged and adverse circumstances,” adds Naresh Narasimhan.

On the usability front, Agilent recently introduced the industry’s first handheld DMM with an OLED display. It functions without a backlight and can display deep black levels and are also thinner and lighter than established liquid crystal displays (LCD). In low ambient light conditions, an OLED screen can achieve a higher contrast ratio than an LCD screen.

“With a 160° viewing angle and a 2000:1 contrast ratio, Agilent’s DMM can be used in pitch dark rooms as well as highly illuminated environments, in which displays of other DMMs are not visible at all,” explains Sadaf Arif Siddiqui.

“Adding to the flock are DMMs with VFD measurement function. Its application is to measure fundamental V+Hz of the VFDs. There are DMMs with oscilloscope and 25 other new models,” says Chandmal Goliya

With the need to constantly innovate to meet customer needs, Fluke’s 233 wireless remote DMM with a removable magnetic display allows taking readings of measurements 30 ft away and is perfect for those difficult measurements where display viewing is a challenge. “With a detachable display, this multimeter is easier to take measurements in hard-to-reach places, or make measurements in machines or panels that are physically separated from a limit or isolator switch. Designed for both convenience and safety, it is ideal in areas where the operator cannot be close to the active measurement point like clean rooms or hazardous areas. Measurements without holding the meter can help users improve their visual focus on their test probes and work more safely. Hence, there’s no more juggling of leads and the meter while stretching towards tight spots,” says Suneel Kapoor.

Some meter manufacturers have taken functionality to the next level. Waterproof meters survive the harshest industrial environments. Automotive meters test alternator diodes, duty cycles, switches and solenoids. Intrinsically safe meters can be used in explosive environments. For serious troubleshooting on electronic equipment or industrial loads, you have advanced DMMs with bells and whistles. Low pass filters to read VSD outputs, and meters that allow you to log and graph data onscreen to capture intermittent problems are some of the advanced features being added to handheld DMMs.

“Fluke has also come up with a 20 series multimeters that can work in the toughest environments. The devices come with the IP 67 (waterproof and dustproof) rating, an extended operating temperature range of -15 to +55 °C and 95 per cent humidity, and have been designed and tested to withstand a 3 m (10 ft) drop. “Fluke 15B, 17B and 18B multimeters set high standards of ruggedness, reliability and accuracy and are available at very affordable prices. These new multimeters also come with user manuals in diverse Indian languages such as Hindi, Bengali, Tamil, Malayalam and Kannada,” adds Suneel Kapoor.

Handheld vs benchtop DMMs

Precision, display, performance, analysis and statistical features/capabilities are some of the key reasons why manufacturers prefer benchtop multimeters over their handheld counterparts. The demand for benchtop multimeters is increasing and the latest DMMs are available with 5½ + 6½ digit displays.

“India has proven to be a hotbed for R&D and electronics design validation. Thus, demand for benchtop multimeters has been rising in India. The demand has also been great from academia and manufacturing,” adds Sadaf Arif Siddiqui.

Manish Kwatra has a different view. “Demand for benchtop DMMs is only increasing in manufacturing but not at the same pace as handheld DMMs because of the shortage of space at service branches. This is also because the features that earlier came only with tabletop models are now available with handheld DMMs,” he explains.

Agilent being one of the leaders in benchtop and system multimeters, offers good performance and reliability at an affordable price.

According to Naresh Narasimhan, there are multiple reasons for the shift to benchtop multimeters. As it usually runs on an AC outlet, it frees one from worrying about changing batteries. Another feature with benchtop multimeters is the 4 wire resistance measurement function. Benchtop multimeters work well for technician stations where multiple meters are employed along with precision multimeters, oscilloscopes, function generators, power supplies and logic analysers. The footprint of the benchtop multimeters works well with other test equipment and if multiple meters are required, the economical line of benchtop multimeter provide a cost effective solution.

However, making the choice between purchasing a handheld or a benchtop DMM is simple. If it is for a design application or for a high degree of accuracy, the benchtop model is preferred. But this accuracy and functionality of the benchtop meters come with a heavy price tag and portability constraint. Prices vary depending on the application and the need. On an average (based on estimates of similar needs), the benchtop precision models are two to four times costlier than their handheld counterparts. While the early handheld DMMs were not accurate, nor did they come with the resolution and advanced functionality necessary to be a versatile instrument on the bench. Today’s feature rich handheld DMMs are packed with advanced functionalities like frequency, pulse width, duty cycle, dB and temperature, besides a computer interface. Thus, the decision of choosing between a handheld or a benchtop DMM is now a matter of personal preferences rather than feature availability.

The accuracy and resolution usually found only in the earlier bench DMMs are now common in their handheld counterparts as well. For example, the Fluke 170 series products have a basic V DC accuracy of up to 0.09 per cent and a resolution of 6000 counts. Fluke 180 series products are a step up with a resolution of 50,000 counts and a basic V DC accuracy of 0.025 per cent. All these meters can be calibrated and have traceability to industry standards, just like their benchtop counterparts. “With specifications like these, it is possible to maintain and calibrate equipment requiring the tightest of tolerances using handheld DMMs. Some DMMs even have onboard memory to save individual measurements or log data over time. Modern DMM designs have display digits that are larger and easier to read than many bench meters and can even display two parameters at once,” explains Suneel Kapoor.

It is clear that there is an increasing overlap of applications where both products can do the same job, as manufacturers keep packing more capability into their handheld meters. The appeal of being able to take a feature rich, high accuracy and low cost DMM into the field for testing, makes a handheld DMM the preferred choice for technicians and engineers alike.

Customisation—the key to survival

With constant innovations and technological changes, customers are demanding multimeters based on their individual requirements, leading to more innovations and customisation in multimeters. In order to serve the needs of the customer and to create a niche for themselves, T&M companies have been customising their equipment. This has enabled users to optimise their performance and reliability. In fact, customisation is the key word for the survival of companies in this segment.

T&M companies work with a mindset of learning from the voice of the customer and they keep introducing product enhancements and enter newer technology areas relevant to their customer base. Multimeters for industrial electricians, plant engineers and technicians, who work in toughest environments are very different from the ones that are used in academia and R&D houses.

It is due to customisation that wireless remote DMMs came into the market. The handheld digital multimeter with OLED displays is also a result of customisation. By introducing multimeters with user manuals in Indian languages, companies have come one step forward in creating a product just for India.

Current price trends

Competition does affect the price of multimeters to a certain extent but more than that, it is the customers who influence costing. “For customers who don’t want to compromise on the accuracy and repeatability, the choice is simple and the offerings are plenty. Moreover, the industry is ready to pay for the technology and features that are required,” says Manish Kwatra.

However, the price for multimeters range from the average to high, depending on the high quality features included in the device. Prices vary from product to product and from model to model, ranging from between Rs 600-75,000, depending on the specifications and features of the multimeters. “Benchtop meters are about 30-50 per cent costlier than their handheld counterparts. With new technology coming in, prices of electronics components are bound to decrease, enabling people to access the latest technology,” adds Chandmal Goliya.

Thinking of buying multimeters? | Here’s what you should look for

While buying a multimeter, always consider the following points—ease of use, (portability, weight, battery life), display (bright LCD, OLED), performance (feature rich, scalable with additional capabilities), ruggedness (safety, water/dust resistant), after sales support and the warranty. Apart from these obvious points, when evaluating the suitability of several digital multimeters, the best approach is to choose a set of measurements and conditions that approximate your application. Choosing a DMM for the job requires not only looking at basic specifications, but also looking at features, functions and the overall value represented by a meter’s design and the care taken in its production. You then need to decide what you want in terms of accuracy, functionality, calibration and build quality.

A solid understanding of specifications is critical when you are evaluating the suitability of DMMs for an application, or you must be confident that your readings accurately reflect reality. First, make sure the qualifiers of each DMM are compatible with the application environment. Then consider all of the functions (DC volts, AC volts, AC amps, Ohms and so forth) and the ranges you are likely to use. Reliability, especially under tough conditions, is more important.

User safety is a primary consideration while choosing a meter. Providing adequate component spacing, double insulation, and input protection helps prevent injury and meter damage when the devices are used improperly. “Make sure you are using a meter that meets the IEC category and voltage rating approved for the environment in which the measurement is to be made. For instance, if a voltage measurement needs to be made in an electrical panel with 480 V, then a meter rated category III 600 V or 1000 V should be used. This means the input circuitry of the meter has been designed to withstand voltage transients commonly found in this environment without harming the user,” says Suneel Kapoor. Choosing a meter which also has a UL, CSA, VDE or TÜV certification means the meter not only has been designed to IEC standards, but has been independently tested and meet those standards.

Finally, look for consolidated requirements to get the ‘quantity benefit’ in pricing and negotiate training as part of the package. You could also pay extra to ensure the investment made in T&M instrumentation pays for itself by maximising usage by the user group.

Note:The names of companies are in alphabetical order

Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine