DM25 Digital Multimeter Yellow

The DM25 Digital Multimeter Yellow is the Greenlee DM-25, a handheld, manual-ranging digital multimeter for measuring electrical parameters up to 600V AC and DC.

What the specs mean in use

• Handheld: a self-contained meter you take to the job, rather than a bench instrument.
• Manual-ranging: you set the measurement range yourself on the meter. You choose a range that suits the reading you expect.
• 600V AC and DC: AC is alternating current, the type supplied by UK mains. DC is direct current, the type a typical camera power adapter delivers. The 600V figure is the upper limit for both.

Where it helps on a CCTV job

A cable run that is too long or too thin can cause voltage drop. When infrared (IR) LEDs draw more power at night, that drop can show up as flickering or a black image. Measuring DC at the power adapter, then again at the camera end, shows how much voltage is being lost along the cable. Compare both readings with the rating on the adapter.

The same meter can check AC supplies before you work on or near them.

The yellow body makes it easy to spot in a tool bag or on a ladder platform.

For a full system you will still need the usual test leads and any other tools for your job. Check what suits the circuits you are measuring.