Tag Archives: multimeter

UT204 is able to measure DC current and also True RMS

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Clamp multimeter UT204 measures reliably even in real conditions of nowadays mains supplies and for an affordable price moreover.

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 of alternating 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), whose output is usually only an approximated sinus.  

That´s why if exact measurement matters to us, it´s more certain to measure by a device equipped by a TRMS measurement. There are many types with this function on the market, and in a segment of clamp multimeters it´s for example the above mentioned UT204, which moreover offers a lot of other functionality for an excellent price.

Detailed information and comparison of UT203/ UT204 will provide you the UT204 datasheet and the UT204 datasheet and UT203-204 user guide. We keep Uni Trend UT204 as a standard – immediately available item.


UT204 is able to measure DC current and also True RMS – [Link]

Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter Review, Teardown & Experiments

In this episode Shahriar reviews the Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter. After a brief look at the instrument’s datasheet, a full teardown is presented. The instrument utilizes a two-board design and a large LCD screen. The SDM3055A provides a comprehensive set of measurements including capacitance as well as various graphing capabilities including histogram, trend and bar graphs. USB and LAN connections are standard and a USB-GPIB can also be purchased. The performance of the instrument is verified through experiments with various functions and setups.

Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter Review, Teardown & Experiments – [Link]

UT61D handles high and also extra low voltages

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That´s why this modern multimeter is also suitable development of sensitive and “ultra low power“ devices.

Wide offer of modern measuring equipment enables us to choose a suitable device for every purpose and in various price levels. A decision which device to buy and/or a decision whether it´s worth to go for a higher-level device surely isn´t easy.

UT61D, which we want to introduce to you this time offers all usual features – at the first sight. But when we go deeper, we find out that besides a pleasant resolution (5999) and a decent precision (0,5-0,8%) it also offers 60mV ranges – for DC and also AC. Especially in the AC field it´s not that common (at equipment of thice price-level) and moreover – all that we measure in the AC signals can be labeled as TRMS (true RMS). And to all this, also measuring of current starts with a 600uA range (DC aj AC), what means measuring with a 0,1uA resolution.

Probably the last main bonus of UT61D is a possibility of communication with PC via serial port (RS232) and displaying of measured parameters in a simple graphic software.

Detailed information will provide you the UT61D user guide as well as UT61 family flyer.

UT61D handles high and also extra low voltages – [Link]

Keithley 7½ digit touch screen DVM

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by elektor.com:

We are used to seeing oscilloscopes with built-in features such as function generators, DVMs and spectrum analysers but now Keithley have switched the tables and produced a DVM or ‘Graphical Sampling Multimeter’ with a built-in waveform capture/display feature. The DMM7510 has a 5 inch capacitive touchscreen interface displaying measurements to 7½ digit accuracy and a waveform capture capability of 1Msample/s using an 18-bit digitiser.
According to the data sheet the DMM7510 features a low noise input stage with a 32-bit A/D converter giving the instrument DC accuracies that are typically only available with metrology-grade instruments. The instrument has good sensitivity featuring 100 mV, 10 ohm and 10 microamp full scale measurement ranges.

The meter also includes measuring ranges for capacitance, ACV and ACI, temperature (RTD, thermistor and thermo-couple), 2- and 4-wire resistance, dry circuit ohms, period, frequency, diode test and DC voltage ratio. In addition to the touch screen GUI the DMM7510 includes a USB 2.0 port to store test results and screen images, a HELP key, a rotary navigation/control knob and a front/rear input selector button. The front panel buttons are backlit and Keithley include their Test Script Processor system and SCPI programming mode. This allows test scripts to be run directly on the instrument without the need for an external PC.

Keithley 7½ digit touch screen DVM – [Link]