Summary of UT204 is able to measure DC current and also True RMS
The UT204 by UNI-Trend is an advanced multimeter improving upon the UT203 model. Its key differentiator is True RMS (TRMS) capability, ensuring accurate measurements of non-sinusoidal AC signals caused by modern switch-mode power supplies and inverters. Unlike standard meters that assume a perfect sine wave, the UT204 maintains precision even with distorted waveforms. Additionally, it retains the UT203's convenient feature for measuring DC current without breaking the circuit.
Parts used in the UNI-Trend UT204:
- True RMS measurement circuitry
- DC current measurement sensor
- Non-interrupting circuit clamp mechanism
- Switch-mode power supply compatibility module
- AC/DC inverter testing interface
UT204 from company UNI-Trend is a near relative to the UT203. multimeter. Already UT203 provides a lot of user comfort and a very pleasant feature – measuring of a DC current without interrupting a measured circuit. However UT204 is different from its “weaker” brother in one essential thing – it enable measuring of a true RMS value ofalternating signals (TRMS).
As we know, usual multimeters usually deploy a simple rectifier and an RC cell and they´re calibrated to show an effective value of AC voltage – supposing an ideally sinusoidal shape of a measured variable.
In many cases, a non-TRMS multimeter is fully sufficient, but still more frequently we meet devices, which by their power consumption significantly deform originally sinusoidal shape of a mains line voltage. A vast majority of new devices is equipped with switch-mode power supplies deforming a sinusoid, as they draw current for charging of input capacitors mainly on a top of a sinusoid. This situation is partially better at power supplies with a power factor correction (PFC), but even in these cases it´s never an ideal load. At any difference from an ideal sinusoid the accuracy of a common meter significantly drops down and the error can exceed tens of percents. Similar situation is also at various DC/AC inverters (for example 12VDC/230VAC
For more detail: UT204 is able to measure DC current and also True RMS
- What is the main difference between the UT204 and UT203?
The UT204 enables measuring true RMS values of alternating signals while the UT203 does not. - Can the UT204 measure DC current without interrupting the circuit?
Yes, the device allows measuring DC current without interrupting the measured circuit. - Why do standard multimeters fail with modern power supplies?
Standard meters assume sinusoidal shapes but fail when switch-mode power supplies deform the voltage waveform. - Does the UT204 work with devices having power factor correction?
Yes, it handles these cases better than common meters though ideal loads are rare. - How much error can occur with non-TRMS meters on deformed waves?
The error can exceed tens of percents when measuring signals differing from an ideal sinusoid. - Is the UT204 suitable for testing 12VDC to 230VAC inverters?
Yes, the article states similar situations exist at various DC/AC inverters which this meter addresses. - What type of signals does the UT204 accurately measure?
It accurately measures true RMS values of alternating signals including those with deformed shapes.
