Many thanks for your interesting review of the FNIRSI SG-004A signal generator and process calibrator meter. Greetings from Stockholm ( Sweden ) and Jan Eklöf

They are very powerful units, given their cost and size and especially when compared to other process calibrators on the market. I think Fnirsi may have labelled them as 'Signal generators' because of their extra functionality and to appear to a wider market than a traditional process calibrator would. The range option allows you to scale the input or output, so you can work in engineering units rather than the raw voltage or amps. So if you have a 4 - 20mA pressure transmitter with a 0 - 10 bar measurement, you can set the input function to 4 - 20 mA and the input range to 0 - 10 to simulate the pressure range. Then when you inject the transmitter the meter shows the mA reading and the corresponding pressure value in the range window. The 24V function can be used to power transmitters either as an auxiliary voltage as you had it wired or using the input terminals it can power a two wire loop-powered transmitter. It looks like yours also has a bit of instability in the measurement function with a fair bit of movement in those last two digits. I would really like Fnirsi to address that with a firmware upgrade so it can then be used a bit more for calibration rather than function checks at the moment.

that some powerful tools considering their sizes . anyway have been expecting this video for a while.

The second format is if you wanted to map the 4-20 mA to an enginnering Units. By default 4-20mA is ranged to 0-1000 but you can change this to what ever range you choose. I actually find this ranging to a process engineering unit useful for temperature, pressure, and percentage open for valves.

Very nice product for the price. Thanks for the review Hugo.

Surely the 24 volts output is for checking 24 volt 4-20mA loops l.e. temperature or pressure transmitters.

Thanks for this video. Specialy the part of testing the in- and output on the same device. I am alwas scared to blow up my meters with that kind of testing.😃Now i can try it without any problem. On my device, SG-004A the 24V output is 24V output, measured on a calibrated Fluke 28II. So it is ok now. Bought the SG-004A last week.

Hi, in frequency output, it is not clear what voltage comes out and its impedance

This small error cannot be due to the temperature.,The calibrations if I'm not mistaken are done at 20 degrees ?

Have you ever put one of these SG-003A on a scope? The one I just bought from Amazon is noisy as hell. Both on CC & CV they are very unstable also - even as measured on the units own v-meter let alone on my fluke and owon DMMs and my scope. I was mostly interested in this device as a low level CCS standard/tool for testing things like phototransistors and as a standard voltage ref for GP use (volts, mv etc that a bench supply would be sloppy at)... but this thing is capricious. As an example, on cv at 3v output (any voltage is same result generally) if you go from a 10k load to 1M, the voltage level changes 100mV! I am not familiar with PLD process meters so perhaps they dont need very tight equipment - but I couldnt IMAGINE this being useful for any sort of testing application. BTW I had it BOTH connected to PC and not connected to PC, with minimal effect (little less noise when not connected - but nothing compared to its general tolerances). I expect a precision v source to have some drop, but not on the level of 100's of mV's for 100's of microamps changes - plus 180mV or so noise SMH.

Did you ever try to convert any engineering unit to Pt100? My device never displays a value above 10.0 °C (103.9 Ohm). The only purpose I bought this unit is to convert 4-20 mA to a Pt100 signal, but it doesn't work. Latest firmware update didn't help.

According to the manual it can be controlled under MODBUS Slave mode and at the end of the manual there are tables of MODBUS functions. But, the manual does not describe how to connect the wiring. Does anyone know how to communicate and control this device using MODBUS (RS485) ?

Can I use it to find data and clock signal of mobile phone cpu?

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