Diode test symbol
The diode test setting. The symbol is the circuit symbol for a diode, a triangle pointing at a bar; on this setting the meter shows the voltage drop across a diode, or OL.
Easily confused with
How to read it
Fluke’s dial guide marks the setting →|, and Klein Tools and Extech print the diode symbol on their dials and displays. Mastech’s MAS838 manual says the setting shows the approximate forward voltage drop of the diode.
Extech’s EX330 manual gives the readings: a diode typically shows 0.400 to 0.700 V one way and OL the other way, a shorted one shows near 0 V, and an open one OL both ways. The MAS838 shows only the figure 1 when the connection is reversed. The test conditions differ by meter: Klein’s MM400 uses at most 1.5 mA at an open-circuit voltage of 3.0 V, the EX330 0.3 mA at 1.5 V, and Fluke’s 115 and 117 show OL above 2.0 V. Fluke’s 114 has no diode test.
Also searched as: →|, arrow with a line symbol, diode symbol on a multimeter, triangle with a line on a multimeter.
These pages describe what each setting, marking and reading means. They are not instructions for measuring anything. Meters differ between makers and models: the meter’s own manual says what each of its symbols means, which measurements it is rated for, and how to use it safely.
Look-alikes
The Continuity symbol symbol, a dot with sound waves, often sits beside it; that setting beeps rather than showing a voltage. On Klein’s MM400 the diode test shares a position with Capacitance symbol, and the SEL button switches between them.
Read next
- Next in Multimeter symbolsCapacitance symbolThe capacitance setting. The two parallel bars are the circuit symbol for a capacitor, and readings are in farads (F), on handheld meters in nanofarads (nF) and microfarads (µF).
- The same shape in P&ID symbolsCheck valveA check valve, which lets flow pass one way and closes if the flow reverses. It is drawn as a Z-shaped break in the line, with a small arrow giving the direction of flow.
More multimeter symbols
The same shape elsewhere
Browse symbols drawn with arrows, lines or triangles.
Sources
- Multimeter Symbols, Buttons, Dials, and Display, Fluke learning centre article, Fluke Corporation, Digital multimeter dial
- 114, 115, and 117 True-rms Multimeters: Users Manual, PN 2572573, July 2006, Rev. 1, 2/07, Fluke Corporation (copy hosted by UCL Electronic and Electrical Engineering), Display; Rotary switch positions
- MM400 Auto-Ranging Digital Multimeter: Instruction Manual, MM400 instruction manual, Klein Tools (copy hosted by UBC Earth, Ocean and Atmospheric Sciences), Electrical specifications; Function buttons
- Mini Multimeter with Non-Contact Voltage Detector, Model EX330: User’s Guide, EX330-EU-ENG V4.2 1/08, Extech Instruments (copy hosted by Core Electronics), Diode test; General specifications
- MAS838 Digital Multimeter: Operator’s Instruction Manual, MAS838 manual, Mastech (copy hosted by Akizuki Denshi), Specifications; Diode test
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
Added .