LCR-T4 electronics components tester ATMega328 - Test and Review

The microprocessor-based electronic component tester will appear in July 2017 in gadgets electroda.pl . The tester automatically detects the type and pinout of the connected component, and displays the measured parameters of the part under test. The tester is powered by a 9V battery and draws 12-15mA while in sleep mode according to the description 20nA (but in practice the current value should be lower, I have not been able to measure the current value in sleep mode).

The component to be tested is connected ever under three (or two) available leads, the measurement starts when the microstick is pressed. Before measuring capacitance, the capacitors to be tested must be discharged. After unpacking the new tester, calibration should be carried out, this is done by connecting leads 1-2-3 together with minimum resistance (e.g. with two jumpers made of silver or redundant resistor terminals). Press the microstick and the calibration begins, at 38% you will be asked to remove the jumpers, at 82% connect a previously prepared capacitor of more than 100nF to leads 1-3.

Type of components tested and parameters checked:
-capacitors: capacitance 25pf-100,000uF, ESR, Vloss
-nPN, PNP bipolar transistors: hFE, Uf
-mOSFET field effect transistors N channel, P channel: gate threshold voltage and capacitance
-jFET junction field-effect transistors: Vgs, I
-diodes and double diodes: conduction voltage and capacitance
-resistors, measurement of resistance of two resistors simultaneously: up to 50MΩ
-Inductance 0.01mH-20H and winding resistance
-thyristors, triacs
Such possibilities are included in the description, but it is worth checking for yourself.

Because one picture is better than many words, below is an animated gif with test results for diodes, bipolar and field-effect transistors, thyristor, resistors, capacitors and inductance, at the end of this text you will also find a video of the device testing.

The accuracy of the M328 tester compares very favourably with a multimeter.
The first column is informatively the type of component to be tested, the second is the result of the multimeter measurement, the third is the uncertainty of the multimeter measurement, the fourth is the result of the tester measurement, in the fifth column the difference between the multimeter and tester readings.

element	multimeter	uncertainty +/-	tester	difference in readings
resistor	118Ω	0,54Ω	117.3Ω	0,7Ω
resistor	9.97kΩ	0,04kΩ	10.18kΩ	0,21kΩ (2%)
resistor	99,4kΩ	0.4kΩ	99, 12kΩ	0,28kΩ
resistor	1,518MΩ	0,02MΩ	1.521MΩ	0,003MΩ
resistor	10,11MΩ	0.2MΩ	10.17MΩ	0,006MΩ
choke	0,107mH / 0.08Ω	0.012mH / 0,06Ω	0.10mH / 0.7Ω	0,007mH / 0.62Ω (775%)
choke	5,14mH / 8.44Ω	0.2mH / 0.09Ω	5.23mH / 8,9Ω	0.09mH / 0,46Ω (5%)
	choke	9,83mH / 14.42Ω	0.3mH / 0.12Ω	10.2mH / 15.0Ω	0.37mH / 0.58Ω (4%)
capacitor	0,28nF	0.03nF	0.277nF	0,003nF
capacitor	4,70nF	0.07nF	4,854nF	0,154nF
capacitor	99,5nF	1.1nF	103nF	3,5nF
	capacitor	983nF	0,01nF	1013nF	a0bebebef971 30nF (3%)
capacitor	100uF	4uF	99,63uF	0,37uF
capacitor	985uF	54uF	968,1uF	16,9uF
diode	0,555V	0.007V	0.683V	0,128V (23%)
diode	0,250V	0,004V	0, 339V	0,089V (35%)

I was really surprised when it turned out that in many cases the difference in the reading is close to the uncertainty of the multimeter measurement. Where the difference was a minimum of 10x the measurement uncertainty I entered the percentage difference from the multimeter result and the tester result. The Sanwa PC500a multimeter was used to measure resistance and capacitance and the UT58D was used to measure inductance.
You can see the error when measuring low resistances of inductive elements, and when measuring the voltage drop on a diode (probably the tester tests diodes with a different current than the multimeter and that is why the differences appeared).
I'm curious to know what the scatter of parameters is and what accuracies the other units of the tester obtain, if you carry out tests with your testers please write in this topic what results were obtained. I will be happy to hear your opinion on this useful device, which, in my opinion, will be useful in every workshop.
As a bonus: changing the firmware and adding my own logo in the LCR-T4.