The bar graph on the Fluke 175 updates about 40 times per second (10 times faster than the digital display). This allows the user to detect changes in readings that occur too fast for non-bar graph-equipped meters to display. Determining whether a TPS, crank sensor or an ABS sensor has an intermittent problem is possible using a bar graph display.
Three other features found on the 175 and other high-quality multimeters are 1) Auto Range, 2) hold and 3) MinMax. The hold button freezes the display when pressed. Pressing the hold button twice switches the display to Auto Hold so that the meter holds the reading until it detects a new stable reading. The meter beeps and displays, and holds the new reading. This feature is useful when you cannot see the meter and want to know whether you have probed a wire that has power or other signal on it.
Pressing the MinMax button tells the meter to record minimum, maximum and average values over time. This is useful when you want to record voltage changes over time and you cannot keep an eye on the display. The ability to record readings works well when you’re trying to figure out intermittent electrical problems. Pressing the button will step the meter through the three readings, while holding the button for one second ends the min/max/avg recording.
The time-saving Auto Range feature senses volt or ohm levels and automatically displays the correct readings by rounding off numbers and correctly placing the decimal point. If you use a less expensive meter that doesn’t have the Auto Range feature, you’ll need to select the correct scale before the meter reading can be interpreted.
For example, to read voltage from a 12-volt battery, the 0-20 volt scale would be selected, allowing the meter to read between zero and 20 volts. Selecting the correct settings for measuring resistance can be more difficult when using a non-auto-ranging meter. If the wrong scale is chosen, the resulting incorrect value displayed on the meter may cause you to unnecessarily replace a perfectly good component.
Other features found on high-quality digital multimeters include amps, frequency, continuity, diode testing, capacitance, temperature, auto shutoff, auto/manual range selection, digital smoothing, internal fuse protection and display backlighting.
You can spend $20 or $500 for a quality multimeter. Just as a $50 car stereo plays the same music as a $2,000 system, all digital voltmeters read electrical values. The one that works for your shop will depend on your level of involvement with powersports diagnostics. Spending more money on a quality multimeter will buy you durability, ease of use, extra features that may provide the only way to figure out a problem, quality meter leads, and availability of accessories and product support.