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Buying guide · 5 min read

Multimeter buying guide: counts, True RMS, safety and the best model for the job

What actually matters when you buy a digital multimeter, with the CIE DM 235 and DM 321T and the Vartech range compared side by side.

By the OhmKart team, Cambridge Instruments & Engg. Co. · Updated 20 October 2026

The short answer

Household and basic electrical work: the DM 235 or the Vartech M 890. Anything with drives, LED lighting or switching loads: a True-RMS meter such as the DM 321T or Vartech V 92. Electronics repair and lab work: the V 980 (20,000 counts) or the bench V 981+.

What a multimeter measures

A digital multimeter reads voltage, current and resistance, and most also test continuity and diodes, with many adding capacitance, frequency and temperature. It is the first instrument for any fault-finding job: is there supply, is this wire continuous, is that component open?

The specifications that matter

Counts and resolution

The count is how finely the display can divide a range. A 2000-count meter shows 1.999 on its 2 V range; a 6000-count meter shows 5.999 on its 6 V range; a 20000-count meter shows 19.999. More counts means finer detail, which matters for low-voltage electronics where a few millivolts decide whether a circuit works. For mains work, 2000 counts is plenty.

True RMS

On a clean sine wave an ordinary meter reads correctly. Drives, dimmers, LED drivers and computers distort the waveform, and an average-responding meter reads wrong. A True-RMS meter reads the real value. If you work near any of these loads, it is worth having.

Auto-ranging or manual

Auto-ranging picks the range for you and is faster and harder to misuse. Manual ranging is simpler and cheaper, and some technicians prefer the control.

Safety category

The CAT rating decides where a meter may safely be used. A meter for electronics benches does not need the rating of one used at a distribution board. Match the meter to where you work, and use leads with the same rating. Our guide to CAT ratings explains the categories.

Useful extras

  • Capacitance and frequency for electronics repair.
  • Temperature probe for HVAC and heating work.
  • NCV (non-contact voltage) to spot live wires without touching.
  • Backlight and holster for site use.
  • PC interface on bench meters if you log readings.

The range compared

ModelCountsTrue RMSRangingDC voltageNotable extras
CIE DM 2352000NoManual1000 VhFE transistor test, capacitance, holster, 9 V battery
CIE DM 321T2000YesManual1000 VBacklight, capacitance, hFE, holster, 2 AA batteries
Vartech V MAS 830 LB2000NoManual600 VBacklit, hFE, holster with stand
Vartech V 830 L+2000YesManual600 VNCV, backlight, torch, data hold, compact
Vartech M 8902000YesManual1000 VCapacitance, hFE, live-wire test, torch
Vartech V 890 D2000YesManual1000 V20 A, capacitance to 20 mF, NCV, frequency
Vartech V 8222 G2000YesManual1000 V AC and DCFrequency, capacitance, temperature
Vartech V 684000YesAuto and manual1000 VDuty cycle, frequency to 20 MHz, capacitance to 100 mF
Vartech V 926000YesAuto600 VNCV, temperature, frequency, capacitance
Vartech V 92 S6000YesAuto with smart detect600 VDual display, bar graph, frequency to 10 MHz
Vartech V 98020000YesManual1000 V0.1% DC accuracy, conductance, hFE, frequency
Vartech V 981+30000YesAuto1000 VBench unit, colour TFT, PC interface

Which one should you buy?

Mistakes to avoid

  • Buying on counts alone. A 20,000-count meter is no use at a panel if it lacks the right safety rating.
  • Measuring current with the leads in the voltage socket. This blows the fuse or damages the meter.
  • Assuming every meter measures AC current. Check the ranges: many basic meters have AC current only on one range or not at all.
  • Using worn leads. A good meter with damaged leads is not a safe meter.
What is the difference between the DM 235 and the DM 321T?

The DM 321T adds True-RMS AC measurement, a backlight and runs on 2 AA batteries instead of a 9 V. The DM 235 is the simpler and more economical meter.

Do I need True RMS?

If you measure only plain sine waves such as a mains socket, no. If you work near drives, LED lighting, computers or chargers, yes.

What does auto-ranging mean?

The meter chooses the right range for the signal, so you simply connect and read.

Can I use a multimeter for insulation testing?

No. For that you need an insulation tester, which applies hundreds or thousands of volts. See the DIT range.

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