FeelElec FR01D Multimeter With Thermal Imaging Camera (Review)

Chinese manufacturers of measuring equipment continue to surprise us with affordable measuring combinations that we would not have thought possible a few years ago. My previous review was about a combination of a scope, multimeter and function generator 2C23T from Fnirsi. This time I got the FeelElec FR01D, a combination of a multimeter with a thermal imaging camera. The FR01D is the latest model in the FR01 series. This type has an IR sensor with a thermal resolution of 192 × 192 pixels, quite a lot when you consider that this device only costs around €200.
 

Is the FeelElec FR01D Usable or a Toy?

When you take the FR01D out of the box, the device appears small with dimensions of 13.5 × 7 cm. Actually, it looks a bit like a toy. The red plastic back is rounded on all sides, which makes the thing unstable on the table. The front is made of gray plastic and accommodates a 2.8-inch color display and four physical keys. The sockets for the multimeter are located at the bottom. At the back we see a vanadium oxide sensor for the IR camera at the top and in the middle there is a lockable cover under which there is a lithium-ion battery for the power supply. Finally, there is a USB-C connector on the side for charging the battery and for connecting to a PC.

Resistive Touchscreen

As already noted, the FeelElec FR01D only has four real push buttons, the rest of the operation is done via the resistive touchscreen. That ‘resistive’ already indicates that you have to press a little harder on the screen than with a capacitive screen as we know from our smartphones today. But it works reliably, you sometimes have to be careful not to select the wrong function because the screen is quite full of all kinds of soft buttons. With the four ‘real’ keys you can switch the meter on and off, switch between IR camera and multimeter, switch on the frequency counter and activate the hold or range function.
 

Many Options, But No Current Measurement

When using the multimeter, the measured value appears at the top in large numbers (9999 counts). Below the display are the keys for the various measuring functions. The meter has an auto-detection function that allows it to determine for itself whether there is an alternating voltage, a direct voltage or a resistance at the inputs. However, this only works at voltages above 0.7 V, below that value you have to switch to a voltage function manually. Furthermore, the meter can measure resistance, diodes, capacitors and temperature, there is a continuity beeper and also a sensor for contactless voltage measurement on live cables. There is even a data logger function where a graph appears on the screen. Current measurement is not possible with the FR01D, but given the dimensions of the housing, some decent fuses for the current ranges would not have fit in there.

Extensive Setup Menu

The FR01D has a setup menu in which all kinds of things can be set. You can choose whether the IR camera or the multimeter is active when switched on, and with which function the multimeter starts. There are also settings for display brightness, sound, switch-off time, USB connection and the internal memory in which screenshots and data logger files can be stored. You can also choose the function of the hold/range push button here. Too bad you can’t use both at the same time because they are both useful functions.
 

In the IR camera settings, you can choose from five different color palettes and the emissivity factor can be adjusted here. The latter depends on the subject to be measured and is important to be able to perform an accurate temperature measurement. Tables showing the values ​​for various materials and objects can easily be found on the Internet.

The FeelElec FR01D Multimeter Is More Accurate Than Its Specs

According to the manual, the specifications of the multimeter are not great with 1% basic accuracy for voltage measurements. But the device I received does a lot better! I tested a number of voltage values ​​and the accuracy appeared to be within 0.2% on average; I also achieved similar accuracy with resistance measurements. With capacity measurements, the measurement error was usually within 1%, which is also excellent for a simple meter. The diode measurement turned out to be suitable for all types of LEDs, including white and blue. For alternating voltage measurements, FeelElec specifies a frequency range of up to 500 Hz, but the range turned out to extend to just over 1 kHz. All in all, good values! The frequency counter even goes up to 30 MHz. At lower frequencies a signal of approximately 400 mV_RMS is sufficient, above 1 MHz this slowly increases to 1.1 V_RMS at 30 MHz.

Altogether the multimeter is very useful for all kinds of electronics measurements. I do have to make a remark about measuring higher voltages: be careful with that! Although 600 V CAT II is stated at the inputs, this has most likely not been tested according to European standards. It is striking that, just like with the Fnirsi 2C23T, the inputs are not placed at the usual distance of 19 mm, but in this case, a few mm more. When purchasing a thermocouple for this meter, it must be one with two separate banana plugs; otherwise it will not fit.
 

High-Resolution IR Camera

Of course, the IR sensor is an addition that makes this instrument special. With this function, almost the entire display is available for the live image. The image is refreshed at a frequency of 20 Hz so that it follows movements reasonably well. The viewing angle is quite large, comparable to a 35 mm lens. The thermal image of 192 × 192 pixels is shown slightly enlarged on the screen (240 × 240 pixels). The temperature of the central spot is shown at the top of the screen and next to it the highest and lowest temperatures that the meter detects in the image are visible as a red and green marked measuring point. Next to the setup button is another button to take screenshots and save them in the meter’s memory. The selected temperature range and date/time are shown at the bottom.

Switching on the IR sensor is quick, it only needs 6 s to warm up. Judging the image that appears on the display takes some getting used to, it all seems quite unclear. After all, the camera only shows heat differences in different colors and if objects on a print or in a room have the same temperature, you only see an even surface. It therefore takes some practice to be able to use it properly (expensive thermal imaging cameras therefore often have a combination of a regular image sensor and an IR sensor, whereby both images are projected over each other). But thanks to the relatively large number of pixels, the FR01D does show a fairly detailed image. If you go very close, for example to accurately measure components on a PCB, everything becomes quite blurry. The manufacturer has designed a handy macro lens for this device at the request of many users, but unfortunately, it is currently hardly available. This could be a useful addition for an electronics engineer.

Use the Correct Emissivity Value

I looked at various subjects with the IR camera, such as a laptop, a Raspberry Pi and a soldering iron. With the latter, I experimented with the emissivity setting, but I didn’t get it completely right. If the camera displayed the temperature of the soldering tip correctly, the ambient temperature turned out to be incorrect again… Using a thermal imaging camera properly is not that easy, you have to know what you are doing and what you need to consider! In any case, the IR camera is a useful tool for measuring the approximate temperature of objects, but also for detecting bad insulation spots in the house.
 

Additional Software for the FeelElec FR01D

Screenshots from the camera and data files from the data logger are stored in the internal memory and can be transferred to a PC via the USB connection. The screenshots are BMP files and the data files are plain text files, so you can easily view or process them. However, FeelElec also offers a simple program to view these files (IR_DMM). The advantage of this is that you can query the temperature of the IR photos with the mouse at any point in the image and the data files are shown in a neat graph. Unfortunately, part of the text is still in Chinese, hopefully it will be translated soon.

Conclusion

At first glance, it does not immediately look like a serious measuring instrument, but the FeelElec FR01D turns out to be a useful measuring device that combines two functions: a multimeter with auto-detection and good accuracy, and a thermal imaging camera equipped with an IR sensor with a respectable number of pixels of 192 × 192. This produces fairly detailed IR images that are useful for detecting components that are too hot on a PCB or heat leaks in the home. For an amount of approximately €200, that is a strong combination!