The EX505 is the entry level multimeter of the EX500 Series from Extech, which also includes the 520, 530, 540 and 570 models. It is a True RMS multimeter with watertight housing, all current ranges and a temperature input.
This Extech EX505 review has a rugged device able to work outside and measure voltage to 1000V and current up to 20A. It also offers a relative mode and auto power-off function, and ships with a temperature probe and magnetic hanging strap.
- Watertight / dustproof case (IP67)
- True RMS capability
- Best DC accuracy: 0.5% (millivolts)
- AC/DC voltage 1000V, current to 20A
- Good capacitance, frequency ranges
- Temperature in Fahrenheit or Centigrade
- Diode, continuity checks
- Electrical, electronic frequency measurements
- Data hold, relative mode
- 4,000 count backlit display
- Auto power-down after 30m
- Size: 7.25″ (184mm) x 3.25″ (83mm) x 2.25″ (57mm)
- Weight: 0.77lbs (349g)
- Meter with 9V battery
- Test probes (3’ leads)
- Type K thermocouple
- Magnetic hanging strap
- Carry case
- Manual (extech ex505 manual)
In-depth Review of the EX505
This meter was designed for industrial and outdoors use, especially tailored to working in humid, dusty factory settings as well as in a marine environment. The DC ranges make it good for both marine and automotive electrical troubleshooting.
Being True RMS responding means it can better accurately measure certain AC drive outputs that have distorted waveforms. It is an auto ranging multimeter too, which is activated by default. A range button lets users select manual range, which can quicken response times. Note: capacitance and frequency are auto range only.
Along with decent voltage and current measuring abilities, the Extech EX505 has a pretty good resistance range (to 40MΩ), as well as capacitance down to 4nF and frequency up to 10MHz. Frequency is dual sensitive, able to measure the frequency of electrical and electronic circuitry.
Although there is no Min/Max record feature on the EX505, it does have a relative mode. This can be used to reference a present reading with a previously stored value, plus you can zero out the resistance in the leads for tighter electronic readings. A manual hold function freezes the display.
|DC voltage||400mV / 1000V||±(0.5%+2) @ 400mV||0.1mV-1V|
|AC voltage||400mV / 1000V||±(2.0%+5) @ 4-400V||0.1mV-1V|
|DC current||400µA / 10A||±(1.5%+3) @ 4000µA-400mA||0.1µA-0.01A|
|AC current||400µA / 10A||±(3.0%+7) @ 10A||0.1µA-0.01A|
|Resistance||400Ω / 40MΩ||±(1.2%+2) @ 40kΩ-4MΩ||0.1Ω-0.01MΩ|
|Capacitance||4nF / 100µF||±(3.0%+5) @ 400nF-40µF||0.001nF-0.1µF|
|Frequency||6Hz / 10MHz||±(1.2%+3) @ 600Hz-600kHz||0.001Hz-0.001MHz|
|Duty cycle||0.1% to 99.9%||±(1.2%+2)||0.1%|
|Temperature °F||-4°F to 1382°F||±(3.0%+9°F) @ <400°||0.1-1°|
|Temperature °C||-20°C to 750°C||±(3.0%+5°C) @ <400°||0.1-1°|
Build and Interface
This is a rugged meter that can withstand harsh environments, with a tough case that has been drop-tested to 2m. The housing is double-molded and is IP67-rated (dustproof / waterproof). On the rear is a kickstand and nicely built in probe holders. The 9V battery is accessible via an outside cover, though the fuses are inside the case. The dial selector is not as solid as some of the top end meters.
Display: with a nice, big screen you get a 4,000-count display that is clear and updates approximately twice per second (this is relatively slow). There is no bar graph on the Extech EX505, but it does have a backlight, albeit one that only stays on for 10 seconds at a time. A battery indicator signifies low battery level.
As is typical for Extech, the rest of the interface is user-friendly, with obvious range positions and a bit of color coding. In addition is an auto-off feature, whereby the meter shuts itself down after it hasn’t been used for 30 minutes. This can also be disabled.
The category rating of the EX505 is CAT-IV for 600V and CAT-III for 1000V. Category 4 means you can use this on 600V systems outside and on the service supply side, with indicated surge protection of 8kV at both rated voltages.
The circuit board is nicely arranged and soldered, with input protection featuring a PTC, power resistor and MOVs. The test lead ends are shrouded on their shanks.
Fuses: both the low and high current inputs are fused, with a 500mA fuse on the mA/µA ranges and a 10A fuse on the high side. Both are HRC, fast blow, 1000V-rated. Although this meter can measure to 20A, it can only do so in short bursts before heating up and inevitably blowing the fuse.
Pros and Cons of the EX505
- Rugged and watertight
- Measures current to 20A
- Features micro-amps
- Auto and manual ranging
- Displays both temperature ranges
- Includes hanging strap, temp probe and case
- Short stock leads
- Temperature readings can be inaccurate
- Continuity response time slow, quiet beeper
- Sluggish auto ranging
This is a tough industrial, outdoors multimeter with a lot going for it, including True RMS response and a temperature input. In the Extech EX505 review, some report hit and miss results regards accuracy. This might be attributed to poor connection(s) at the probe jacks due to it being watertight. A higher quality set of leads would likely see better performance.
Alternatives: a bit more expensive but the Amprobe AM-570 has similar specs and more accuracy and functionality. The Klein Tools MM1000 is also similar and cheaper, but is minus True RMS, though this is only really essential for measuring AC variable drive systems.