This fairly compact, True RMS AC/DC amp clamp meter is for electricians and plant maintenance engineers. Measuring up to 400A in both AC and DC systems makes it more useful than your average clamp meter, plus it also does voltage, resistance, capacitance, frequency and continuity. The Fluke 325 review effectively sees a full multimeter with the ability to also measure high current.
- Measures AC/DC current to 400A
- AC/DC voltage to 600V
- Resistance to 40kΩ
- Capacitance and frequency
- Temperature input
- True RMS response
- CAT-IV safety rating
- Slim & ergonomic
- Min/Max and screen hold
- Size: 8.15″ (207mm) x 2.95″ (75mm) x 1.34″ (34mm)
- Max core size: 1.18″ (30mm)
- Weight: 10oz (283g)
- Test leads with shrouds
- Batteries (AAA x2)
- Instruction booklet (fluke 325 manual)
- Soft carry case
In-depth Review of the Fluke 325
As the top model of the 320 series of clamp meters, the 325 has the overall best feature-set. The 323 can only measure AC current and is without temperature, capacitance and frequency, for example. Despite the extra functionality, it is still small and rugged, allowing the user to get into tight spaces and cable ducts.
This device is ideal for establishing load currents of motors, mains voltage in home circuitry and continuity in switches, etc. There are two amperage ranges. The CAT-IV rating means you can measure systems in industrial environments also, and the inclusion of capacitance and a temperature input makes it useful for many HVAC tasks. Users can also check current draw and ignition systems in the automotive world.
The jaw size of the Fluke 325 is fairly standard, at 30mm; while True RMS capability lets you diagnose non-standard wave forms. DC amperage can be measured below 100mA.
The probe leads are around 4 ½ ft long and are of good quality, with detachable shrouds for added safety. The included thermocouple (which plugs into the same jack sockets) is a little under 3ft and the display can read in Fahrenheit or Celsius. You also get a backlit screen, where lower models don’t have this. Modes include Min/Max for recording low/high readings in a signal, and data hold.
Accuracy is okay for a clamp meter and within tolerance of most electrical tasks. Along with the type-K thermocouple, this meter also comes included with a soft carry case. There’s a booklet for basic usage, and you can also view and download the full manual freely online (see above).
|AC current (45-65Hz)||40A / 400A||±(2.0%+5)||0.01-0.1A|
|DC current||40A / 400A||±(2.0%+5)||0.01-0.1A|
|AC voltage (45-400Hz)||600V||±(1.5%+5)||0.1V|
|Resistance||400Ω / 40kΩ||±(1.0%+5)||0.1-10Ω|
|Capacitance||100μF / 1000μF||±(1.0%+4)||0.1-1μF|
|Frequency||5Hz / 500Hz||±(0.5%+4)||0.1Hz|
|Temperature||-10°C to 400°C||±(1.0%+8)||0.1°C|
This brand produces some of the best meters and the Fluke 325 review has a well built and rugged device. You get a sure clamp, easily opened, and a steady dial selector switch. The leads plug into the bottom, with less chance of snagging while taking current measurements. The thermocouple has a sturdy plug that occupies the same jack inputs as the probe leads.
Display: You don’t get amazing resolution – clamp meters are not known for being hi-res – but it is 4000-count and displays down to 0.01A. Some of the comparable amp clamps have bigger screens, like the Klein CL1000, but it does have a backlight.
Function and Performance
It performs fairly well. Being an auto-ranging device, you don’t need to select individual ranges as with manual ranging meters. The auto-range speed is okay for a meter of this standard, while continuity mode has a latching beeper and is quite quick. As it’s powered by AA batteries, overall efficiency is good and they are cheaper to replace than a 9V battery.
Rating protection levels on the Fluke 325 is CAT-IV at 300V and CAT-III at 600V. You can thus work on building source voltage (to 300V) and everything behind the circuit breakers at 600V. Surge protection at these ground voltages is to 6kV.
Pros and Cons
- Can measure DC as well as AC current
- Includes typical multimeter ranges
- Can measure temperature (probe included)
- Backlit display
- Not bulky
- Includes a carry case
- Pricey compared with other brands
- Few other cons, though a hanger would be nice
With the Fluke 325 review, you get one of the better amp clamp meters on the market. It can measure DC and AC amps (few measure both) and can read most of what a traditional multimeters measures to a certain degree of resolution. This is the top of the 320 series, having extras like capacitance, frequency, a backlit screen, Min/Max mode and temperature. It is ideal for those solely into electrical trades, but can’t replace a good hi-res meter used to diagnose electronic circuitry.
Alternative: Amprobe and Klein Tools both make good clamp meters, too.