When you are responsible for installations, maintenance, repairs, and overhauls of "everything industrial," your toolbox can fill up pretty quickly with all the tools and test equipment needed to constantly change gears from job to job. Jobs can range from electrical testing on pumps, motor controls, and boilers, to heating and cooling measurements, to lift and conveyance systems diagnostics, to furnace, flame signal, and compressor troubleshooting. For many of these jobs, a multi-function clamp meter designed for the industrial setting can help you with essential electrical readings such as current, voltage, and temperature. For most clamp meters, "multi-functionality" means having these three essential functions in one tool: a clamp meter, a multimeter and a thermometer capable of readings via an external Type-K probe. But the truth is, the complexity of today’s plant systems demands other functions as well, such as non-contact voltage detection, non-contact infrared temperature readings, and thermometry capabilities to take temperatures at two different spots.
You quickly realize that besides carrying a 3-in-1 clamp meter, you need numerous other test devices to get your job done effectively and safely. Ideally, your clamp meter should be equipped with additional functions to help you save on equipment spending and to get more done with less equipment.
Here are examples of other important testing functions that an industrial MRO professional uses day in and day out:
An infrared (IR) thermometer is indispensable if you need to measure temperatures at a distance due to limited access or safety issues. With a built-in laser beam to ensure precise targeting of the desired measurement spot, an IR thermometer is as quick as it is useful. While a 3-in-1 clamp typically does offer Type K one input for temperature readings, an IR thermometer can prove handy in a number of situations. Examples include: measuring air temperature from a ceiling duct; taking a reading on a live surface such as a circuit breaker or motor control; performing spot maintenance checks to see if motors or bearings are running too hot; or scanning evaporator coil and suction line temperatures for abnormal readings.
Differential Temperature Type K Thermometer
On the subject of temperature, getting a differential temperature reading or "delta T" from two different areas in a refrigeration system determines superheat or subcooling temperatures. These versatile values can help a technician isolate problematic HVAC issues such as under- or overcharge, an overfeeding metering device, restricted or misdirected airflow, restrictions in refrigerant liquid lines, or insufficient condenser cooling from poor air or water flow. To get a delta T measurement, you need to perform two temperature measurements.
If your clamp-meter only features one Type-K thermocouple input, you'll need another device such as a multimeter or a separate Type K thermometer to get that second simultaneous reading. In some cases, technicians use a dual type-K thermometer to take both readings. With dual temperature probe inputs and a built-in T1 minus T2 function, a dual thermometer automatically gives you a differential value that is useful in determining the superheat or subcooling temperature for a refrigeration system without temperature charts and without a calculator.
Non-Contact Voltage Detector
One safety and diagnostic must-have is a non-contact voltage detector. If you are on a site where vital equipment is down for example, and you need to check quickly and easily for the presence of voltage around an area where repairs need to be performed, a non-contact voltage (NCV) detector is invaluable. With an NCV detector, this vital first-step safety check easily alerts you with visible and audible alarms if live voltage is nearby that should be avoided or powered down.
Finding Best-in-Class Functionality
MRO professionals should keep the following specifications in mind when selecting clamp meters and related test equipment:
INFRARED AND TYPE K THERMOMETERS
A Newer, Economical Alternative: Industry’s First 5-in-1 Clamp Meter
It’s clear from this buyer’s guide that, for effective industrial plant troubleshooting techniques, multiple tools are frequently required. One company is taking a different approach suggesting that multiple functions are required, but not always multiple tools. Extech Instruments recently introduced their EX623, the industry's only 5-in-1 clamp meter. In addition to standard 3-in-1 capabilities found in most clamp meters (clamp meter, true-rms multimeter, and Type K thermometer), the EX623 offers a built-in infrared thermometer (a patented Extech feature) and an integrated non-contact voltage detector. Additionally, its thermocouple-based thermometer is upgraded to two Type K inputs and offers an automatic differential temperature function. The EX623 costs significantly less than a set of similar, separate tools and also takes up less room in the toolbox.
By combining key testing functions that a plant MRO technician uses day in and day out with best-in-class specifications, the Extech EX623 is receiving many positive reviews around the world. The 5-in-1 was recently awarded the Gold Industrial Electronics Innovation and Technology Award at the Hong Kong Electronics Fair, Asia's biggest electronics event. Judges at the competition remarked that award winners not only demonstrated sophisticated product designs, but also reflected appealing value in this challenging economic climate.
Smart Techs Looking for Smart Tools, Smart Buys
It’s easy to see why technicians rely on the versatility, ruggedness and accuracy of their testers and meters. Whether it’s 3-in-1 versus 5-in-1, or the indispensible use of non-contact tools such as IR thermometers and voltage detectors, the test equipment market has changed dramatically in recent years. While some buyers will always shop by brand, many more are taking a closer look at side-by-side comparisons of product specifications before opening their wallets. With this multifunction clamp-on meter guide in hand, buyers can identify key functions and specs that should be on everyone’s must-have list. After all, for many technicians, shopping for new test equipment not only means finding a smart tool but a smart buy.