Autool DM400 | Multimeter
Warranty directly via AsTools
Warranty directly via AsTools
We handle warranty cases ourselves, quickly and without involving the manufacturer. Thanks to our own parts inventory and technical expertise, we can usually assist you immediately. Only in exceptional cases do we still send the product to the supplier.
2 years warranty on all products
2 years warranty on all products
All our products come with a 2-year factory warranty. This ensures you long-lasting quality and service.
Easy returns
Easy returns
You can easily request your return through your account. We will send you the return label by email. Return shipping costs are your responsibility.
Professional customer service
Professional customer service
Our experts are ready to help you quickly and professionally, both online and in our physical store. Questions? Feel free to contact us!
The Autool DM400 is a digital True RMS multimeter designed to measure a wide range of electrical parameters. This instrument uses True RMS technology to deliver accurate readings of both sinusoidal and non-sinusoidal AC waveforms. The multimeter features a 6000-count LCD display with backlight for clear visibility.
Functions include AC/DC voltage and current measurement, resistance, capacitance, frequency, duty cycle, and temperature (-20 °C to 1000 °C via the included K-type thermocouple). The DM400 meets safety standards CAT III 1000V and CAT IV 600V — suitable for work on household and distribution networks.
KEY FEATURES
IMPORTANT NOTES
Applications and functionality
The DM400 is ideal for electrical measurements across diverse applications: from household use to professional and industrial environments.
- True RMS measurement: Accurate AC voltage/current independent of waveform.
- Data hold and Max/Min: Freeze readings or capture peak values.
- Temperature measurement: Included K-type thermocouple for °C or °F display.
- Auto/Manual Range: Automatic or manual measurement range selection.
- Backlit Display: Large LCD screen with backlighting.
- Safety Rating: CAT III 1000V & CAT IV 600V.
Measurement Ranges and Functions
- DC Voltage: 0.1 mV to 1000 V
- AC Voltage (True RMS): 0.1 mV to 750 V
- DC Current: 0.1 µA to 20 A
- AC Current (True RMS): 0.1 µA to 20 A
- Resistance: 0.1 Ω to 60 MΩ
- Capacitance: 10 nF to 10,000 µF
- Frequency: 1 Hz to 10 MHz
- Temperature: -20 °C to 1000 °C
- Duty Cycle: 1% to 99%
- Continuity Test: Audible alert for low resistance
- Diode Test: For semiconductor diodes
Package Contents
- 1x Autool DM400 digital multimeter
- 1x Test lead set
- 1x K-type thermocouple
- 1x User manual
Technical specifications
General
- The manufacturer of the multimeter or test lead set.Brand
- Autool
- Whether this is a standard multimeter, a multimeter designed specifically for cars, or a separate lead set. This shows at a glance what you are buying.Device type
- Digital multimeter
- A True RMS meter measures AC voltage and current accurately even when the signal is not a clean sine wave, as is often the case in a car.True RMS
- Yes
- Whether the meter selects the correct measuring range automatically or you set it with the rotary dial. Automatic is faster and easier.Range selection
- Automatic and manual
Safety
- Indicates at which voltage and installation type you can measure safely. A higher CAT rating offers better protection against voltage spikes.Safety category
- CAT III 1000V
- CAT IV 600V
Measuring ranges
- The highest DC voltage you can measure. 60 V is sufficient for a conventional car, while hybrid and electric vehicles require more.Maximum DC voltage
- 1.000 V
- The highest AC voltage you can measure, for example at a charging point or an alternator.Maximum AC voltage
- 750 V
- The highest current you can measure directly through the meter. A higher rating is useful for tasks such as tracing parasitic drain.Maximum current
- 20 A
- The highest resistance the meter can measure, for example of sensors or wiring.Maximum resistance
- 60 MΩ
- The highest frequency you can measure, useful for signals from sensors and injectors.Maximum frequency
- 5 Hz – 10 MHz
- The largest capacitor value you can measure.Maximum capacitance
- 10,000 µF
- The temperature range you can measure using a temperature probe.Temperature measuring range
- -20 to 1,000 °C
Functions
- What you can measure besides voltage, DC current and resistance. More functions mean you can diagnose more faults with one device.Measuring functions
- AC current
- Capacitance
- Frequency
- Duty cycle
- Temperature
- Diode test
- Continuity test
- Convenient buttons that make measuring easier, such as holding a reading or recording the highest value.Additional functions
- Hold reading
- Maximum and minimum reading
- Automatic shut-off
Display
- How many steps the display can show. More counts means you can read smaller differences more precisely.Display resolution in counts
- 6,000 counts
- With backlighting, you can read the display clearly under a car or in a dark engine bay.Display backlight
- Yes
Dimensions and weight
- Which batteries power the meter.Power supply
- 2x 1.5 V battery
- The ambient temperature at which the meter operates correctly.Operating temperature
- 0 to 40°C
- Whether a thermocouple is included, so you can measure temperature straight away without buying anything extra.Temperature probe included
- Yes
Other specifications
- Display
- 6000-count LCD with backlight
- Range Selection
- Auto / Manual
- Sampling Rate
- 3 times per second
- DC Voltage
- 600 mV / 6V / 60V / 600V / 1000V
- AC Voltage
- 600 mV / 6V / 60V / 600V / 750V
- DC/AC Current
- 600 µA / 6000 µA / 60 mA / 600 mA / 20 A
- Resistance
- 600 Ω / 6 kΩ / 60 kΩ / 600 kΩ / 6 MΩ / 60 MΩ
- Auto Shutoff
- Yes (manually disableable)
- Operating Environment
- 0 – 40 °C, RH <80%
