An Update on Meters

1975–2025: A look back.

By Ed Butts, PE, CPI

Perhaps there is no other part of the water well and pump business that has demonstrated more radical changes over the many years I have worked in the industry than test meters.

Figure 1. Square D voltage tester—“Wiggy”.

There were a few tried and proven meters we were told to use for troubleshooting well pumps, especially submersible pumps, when I started in 1974. For the most part, I rigidly adhered to the instruction, as what choice did I really have?

As time passed, however, my need for what I considered “really neat and cool” new electronic gadgets along with the introduction of so-called “new and improved” instruments for diagnosing and troubleshooting electrical systems led me down a path of spending more money with often questionable results or returns.

In this month’s Engineering Your Business, we will explore the rich history of electrical test meters in 1975 and examine the most recent improvements in testing equipment and try to answer that one overriding question: Are they really that much better today?

Figure 2a. Amprobe RS-3 voltage test meter.

Disclaimer: The information contained in this column is for the sole benefit and education of individuals who are adequately knowledgeable, trained, and experienced with using electrical test meters on high and low voltage AC and DC electrical power and circuits. As is always the case when working around electrical power supplies and circuits, safety must be the paramount consideration.

The information contained within this column has been formulated from the personal experiences and background of the author and shall not be construed as any endorsement or recommendation of or use of any specific instrument or test method. The use of any information contained within this column shall be at the sole risk and responsibility of the reader.

The Good Old Days of ’75

As a confirmed old-timer with more than 50 years in the business, I feel that I more than qualify to voice my opinion on the changes we have seen in electrical testing equipment over the past five decades.

Figure 2b. Amprobe RS series meter with a flat scale.

Although my experience has certainly included the revolution seen in digitally based electronic equipment and the resultant loss of some fine and still usable analog test equipment, I nonetheless cannot claim to have firsthand experience with all the various types of electrical test gear that was available and used during the 1950s and 1960s.

Submersible well pumps were just starting to increase in use and popularity in the 1950s. Most well pumps such as vertical turbine, jet, and rod pumps were still largely mechanical in design and configuration, so repair, troubleshooting, and electrical test meters were largely confined to using instruments to simply determine if AC voltage was or was not present at or around fuses or circuit breakers and verify the current draw of the motor.

For voltage checks, after examining the various test methods available for checking voltage, I settled on a simple voltage tester. This device, better known in the electrical industry by its adopted name of “Wiggy” (Figure 1), is still made and is an excellent, easy-to-read, and safe instrument for verifying the presence and level of AC and DC voltages.

It is a low-cost (about $150), compact, and portable instrument with permanent test leads that easily fits into a back pocket, tool pouch, or bag. Plus, it’s extremely rugged. I quickly bought and adopted a Square D Wiggy as my primary method for quick voltage checks. Various versions of this tester are also made by several other manufacturers.

Figure 2c. Amprobe RS series digital meter.

Based on discussions with some really-old-timers in the pump business I used to work with, the two must-have meters in their toolboxes back then were often a combined amp/volt meter, also known as an ammeter, and an ohmmeter or a crank-generated megohmmeter, also known as a megger, for checking the insulation resistance of motors.

To this day, my primary amp/voltage test meter is an Amprobe model RS-3 (Figure 2a). Typically, amp meters are available in three styles: a meter with a vertical scale, such as the Amprobe RS series, a meter with a flat scale (Figure 2b), and a digital meter (Figure 2c).

Although I recognize many of you have converted to using digital test meters, such as those made by Extech or Fluke, I am the kind of guy who likes to stick with what I know, so I tend to stay loyal to the meters that have worked well for me for many years.

The Amprobe RS-3 is a rugged, accurate, and versatile meter for checking AC volts and amps and it remains my No. 1 go-to meter. The only downside is the ohmmeter plug-in probe included with the RS-3 model, as it requires a battery and I feel is not accurate and only good for quickly checking fuses.

Figure 3. Simpson model 372 ohmmeter.

The Simpson model 372 ohmmeter (Figure 3) is the undisputed king of test meters for testing the resistance of submersible pump motors and control box components. In fact, it is the meter that has been consistently cited in the Franklin Service Manuals over the years as the primary test meter for checking submersible motors and control box components.

Irrespective of the 30-volt battery you must periodically replace, I think the Simpson 372 is simply the best and most economical submersible motor troubleshooting meter you can buy. Routine calibration is easy, and the rugged case helps avoid damage to the instrument and provides space for the leads.

Figure 4. Franklin Electric’s SubCheck ohmmeter.

Speaking of Franklin Electric, let’s talk about its early contribution to the world of electrical test meters. I believe Franklin Electric is truly one of the finest manufacturers of water well-related equipment in the industry as its contribution to advancing technology and submersible motor design cannot be disputed. However, in my opinion, as far as electrical test meters are concerned, Franklin’s early contribution was disappointing.

The often cumbersome and fallible process of capturing and interpreting readings from the Simpson 372 led to Franklin Electric’s introduction of the SubCheck ohmmeter (Figure 4) in the early 1970s.

This device offered a submersible motor oriented color-coded scale, providing instant answers to insulation and winding resistance values, making it easier for pump installers to accurately assess motor health. It was a diagnostic tool to check motor windings, motor and cable insulation resistance, control box relays, overloads, and capacitors, along with fuse continuity.

Figure 5a. Fluke 789 analog meter.

When this device came out, I simply had to have one, as I thought this was it—a test meter those of us in the pump business can call our very own as it is specifically designed and built to troubleshoot submersible motors and control boxes. By nothing more than connecting the two test leads and pressing a button, I believed we would be able to show our customers if their motors were either good or bad.

I remain convinced the concept is good and wish we had something like it now, but the meter itself wasn’t great. For example, as with the Simpson 372, the needle could not be locked down, which made retaining an accurate calibration problematic after bouncing along in a service truck.

In addition, there was no way to check voltage or amp draw, which severely limited the versatility and usability of the meter. There was a button on the top of the case that had to be pushed down and held while obtaining a reading, which meant that you needed three hands at times to use it. The needle took what seemed like forever to swing into its final read position, it was far too sensitive (as all ohmmeters are), and there was no protective case provided with the meter.

Figure 5b. Fluke 87V multimeter.

Even with all these drawbacks, I still used my Subcheck for more than a year until it finally blew up one day when my helper inadvertently connected the leads to a live power source!

I sincerely think if Franklin had used more innovative thought, it could have developed a reliable test meter with a different rotary selection switch for amps, volts, or ohms (perhaps limited to 600 VAC and 100 amps), a second rotary selector switch for ranging, a clip-on amp loop for reading amps, expanded scales, and eliminated the push button.

Even with all of this talk about analog meters, that is not to say that I do not have or use digital meters. I actually have quite an assortment of them that I regularly use for testing sophisticated and complex control circuits, such as low and high voltage power and DC milliamp/millivolt paths and controls, SCADA (Supervisory Control and Data Acquisition) tone signals and related circuits, and variable frequency motor drives. Most are made by Fluke.

Figure 6. Digital megohmmeter.

These include such meters as the Fluke 789 analog meter (Figure 5a). This meter is a valuable addition to 4-20 mA DC analog circuit calibration and troubleshooting tools as it is capable of directly reading an externally driven analog signal by inserting the meter into the analog loop as well as generating an internal adjustable signal for instrument testing and calibration.

Another popular and versatile multimeter is the Fluke model 87V (Figure 5b), which is largely used to verify values of True RMS (Root-Mean-Square) voltages in VFDs and control circuits. In fact, I own a personalized and see-through Fluke model 87 that the firm was gracious enough to send me to assist with product testing and feedback.

Even in 2025, what routinely rides along with me in my vehicle—the meters I trust, need, and use the most—are mainly the Amprobe RS-3 ammeter and Simpson 372 ohmmeter.

The New Electrical Test Meters

Figure 7. Non-contact voltage testers (detector pens).

In our current world of electronic devices like VFDs and solid-state controls, the use of a digital meter for calibration and troubleshooting purposes is almost a given. Beyond the Fluke 87 and Fluke 789 meters mentioned above and other assortment of digital equipment, I also use a 1000/500/250VDC digital megohmmeter (Figure 6) for checking the high voltage values of insulation resistance on various electrical devices.

This uses a capacitor to build up the test voltage, a definite improvement over the older hand-cranked version I used to own. I also have a portable oscilloscope/waveform meter for checking electrical sine waves associated with VFDs and reduced voltage motor drives, and finally, a specialized meter used to generate, calibrate, or read the multitude of process variable signals such as milliamp or millivolt circuits commonly used in today’s water pump control systems.

Figure 8. Three-phase power analyzer.

Each of these meters has a definite and individual capability and I maintain them all for use at a moment’s notice, but do not normally carry them with me.

There have been other notable changes to electrical test meters since 1975. A few decades ago, we saw the introduction of non-contact voltage detectors in a pen configuration (Figure 7) that can easily fit inside a shirt pocket. Several electrical manufacturing firms make and sell these, including Square D (now Schneider), Ideal, Klein, and Fluke. These illuminate a small LED bulb when the tip of the pen nears AC voltage up to 1000 volts. I know many electricians and service technicians swear by their reliability.

Many other new meters and test instruments are in response to advancing technology in digital electronics. For example, a power quality and motor analyzer is used to evaluate electrical and mechanical performance from pumps and motors. Another valuable meter is a three-phase power quality analyzer (Figure 8) used to evaluate three-phase power quality logging, troubleshooting, and providing system analysis.

Many of these instruments also possess recording capabilities, allowing the meter to be connected to a power source to track and record system parameters over a day or a few weeks of use.

Figure 9a. Powers water level meter.

Other instruments can conduct testing valuable to analyzing pumping and motor systems, including vibration analysis, thermal imaging, infrared detection, and laser alignment. There are also instruments that can evaluate and calibrate solar panels and fiber optic circuits as well as conduct network and mesh analysis.

Output data from these instruments, as well as newer flowmeters and water level and quality sensors, can now be routed to and stored in data loggers or transmitted to other electronic storage devices for subsequent use and reference.

Finally, while I have mainly cited Fluke instruments, I am not ignoring the many other firms that manufacture electrical testing meters. There are numerous manufacturers of testing equipment with comparable performances.

Flowmeters

Figure 9b. Fisher “M” scope.

Closed and open channel flow indication in 1975 was traditionally performed using either velocity, volumetric, or pressure or head differential methods. Velocity meters included propeller flowmeters; volumetric included turbine meters; while pressure (head) differential methods included annubars (orifice), weirs, and flumes.

Technology since then has greatly expanded with the introduction of electronic (mag) meters, ultrasonic meters, vortex and swirl meters, and coriolis meters.

Electronic flowmeters, one of the most popular current types, typically consist of a primary device (the flow measurement means a uniform or converging section or an inline tube), transducer, and transmitter. The transducer senses one or more of the fluid or velocity parameters, such as solids or entrained gas content, cross-sectional velocity (time-transit), pressure differential, or signal bounce/rebound time, that are developed as the media passes through the primary flow measuring device.

The transmitter produces a flow display and output signal from the raw transducer signal. These three components are often combined into a single assembly, so that the actual flowmeter may consist of only one physical device.

Water Level Meters

Figure 10. Ravensgate sonic water level meter.

One of the principal advancements in water well measuring instruments since 1975 is undoubtedly the evolution of ultrasonic and similar meters for reading water well levels. When I started, we used two principal methods for reading water levels: airlines and electronic meters that used a suspended cable. These were the Powers water level meter (Figure 9a) and Fisher “M” scope (Figure 9b).

A recent advancement in reading water levels is the sonic meter. The Ravensgate sonic water level meter (Figure 10) is a non-intrusive device that transmits acoustic (sound) waves down the interior of a well casing that can otherwise be hard to access because of a crooked pipe, narrow diameter, or other obstacles.

Figure 11. Well Watch 670 water level meter.

When the sound waves bounce off the water’s surface, they return to the meter. The time traveled by the sound waves is measured and analyzed, and the data is displayed on the LCD screen as feet or meters. This is like sonar on a submarine. The device is lightweight, portable, and provides an alternative to airlines and conventional water level meters.

A similar instrument is the Solinst sonic water level meter. This meter is designed to sit in the vent opening of a standard well cap, or the opening of a locking well cap. A reading is obtained within seconds of turning the meter on. Larger diameter wells or wells with large openings can limit sound wave detection, but with adjustments, accurate water level readings can be obtained.

Another sonic water level meter provides continuous water level indications. This signal can be used to continuously record (log) water levels, control a pump, or provide a safety shutoff for low water levels.

A common method consists of an electronic “strain-gauge” transmitter that continually transmits an analog voltage or current signal to the surface. This device reads the submergence (water head) over the device with the signal sent to and interpreted in a relay that then sends it to a control or monitoring device.

Figure 12a: Groundwater sampling assembly.

The Well Watch 670 (Figure 11) is a line of sonic water level meters designed for semi-permanent installation that also uses sound waves. The Well Watch 670 includes an external display with keypad which allows the user to view real time data and to easily control the internal settings. It also has a built-in data logger capable of logging up to 25 million time/date stamped data points. This gives the user the ability to store long-term well level data and trend usage levels.

Water Quality Sampling Devices

A significant advancement since 1975 is the increased growth and selection of water quality samplers for environmental uses. Water sample pumps (samplers) are now available to continuously or intermittently monitor and test single or multiple surface water, groundwater, and wastewater quality parameters such as turbidity, hardness, iron, manganese, temperature, heavy metals, and many other parameters and regulated and non-regulated contaminants.

Figure 12b. A 2-inch environmental submersible pump.

The sampler is generally suspended from either a submersible power cable or small tubing on a reel, which also acts as the conduit to convey lower head water to the ground surface, with the sampler operated from an adjacent controller (Figure 12a).

The sample is thereafter delivered to an onsite analyzer or offsite laboratory. These devices are typically designed for low-rate pumping (5-20 ml/minute) at moderate heads of 250 feet or less and can be styled for active, online grab samples, or continuous delivery from a production, monitoring, or observation well.

Other groundwater samplers use a centrifugal or positive displacement (helical rotor, peristaltic, or bladder) submersible style of pump. These are often operated using a 12- or 24- volt DC submersible motor and specialized controller.

Groundwater samplers can be designed to work in diameters as small as 1 inch to depths of 1000 feet or more. Many of these devices operate from a variable frequency drive, which permits pump operation at variable frequencies to function at various flowrates and/or head. Figure 12b illustrates a 2-inchdiameter
environmental sampling submersible pump and motor for obtaining representative water samples from an
aquifer or well at flow ranges between 100 ml/minute up to 8 GPM at heads exceeding 300 feet. These devices will undoubtedly continue to grow in type, popularity, and diversity.

Thermal and Infrared Cameras

Finally, one of the most intriguing and important developments for electrical troubleshooting since 1975 has been the introduction of infrared and thermal cameras.

Infrared cameras capture images by detecting infrared light invisible to the human eye but emitted by objects as heat. Unlike standard cameras that rely on visible light, infrared cameras create images in low-light or dark conditions.

Thermal cameras, on the other hand, detect heat radiation emitted by objects. By measuring the differences in temperature, they create heat maps that represent warmer and cooler areas in varying shades of color.

Thermal cameras are invaluable in industries where detecting temperature variations is critical, such as examining the difference in operating temperature between conductors or terminals or identifying hot spots on motors. They are now widely used for industrial monitoring and inspections such as detecting overheating electrical equipment, motors, machinery, and more.

Infrared cameras are more affordable and widely available from several manufacturers, while thermal cameras are typically more expensive and less available due to their advanced capabilities. In fact, infrared cameras can be procured for under $1000 while thermal imaging cameras can cost 10 times or more that amount.

Before investing in either type of camera, it is essential the prospective buyer evaluate their exact needs and type of diagnostic work they do. Examples of thermal and infrared cameras are shown in Figure 13a, Figure 13b, Figure 13c, and Figure 13d.

______________________________________________

This wraps up our overview of advancements to various types of test meters. Constraints on space do not allow more than an outline of the improvements made to this technology since 1975. However, please feel free to write in and regale me with stories regarding your personal history of test meters.

We’ll look back next month on 50 years of business, regulatory, scientific, and societal changes. So, as always, until next month, work safe and smart.

Ed Butts, PE, CPI, is the chief engineer at 4B Engineering & Consulting, Salem, Oregon. He has more than 40 years of experience in the water well business, specializing in engineering and business management. He can be reached at epbpe@juno.com.