PICO Technology TA189 AC/DC oscilloscope current probe Review 5mA~30A Low Noise

[Kiriakos GR]

PSU waveform this is most polluted with noise, it is in the nature of this technology to behave that way. 
Tomorrow I will run the last pack of tests, and this is Phase Shift stability and Min/ Max in all three loads.

The upcoming statistics will help me so I to evaluate my oscilloscope performance in contrast to the new scope (when ever I will get one).

Unfortunately for me and for GW Instek, I did hit a wall due the 8 bit resolution of my Oscilloscope.
I was feeling optimistic that by a special probe alone I could go further in power analysis. 

Even up to date (7-2023),  GW Instek this does not have ready any 12 bit scope so to compete in this market.
I am very bonded now with GW Instek oscilloscope user interface ( menu, buttons, and where its setting this is placed).

For now I will have to set a pause, and wait if in the future, GW Instek succeed to deliver 12 bit scope at a reasonable pricing.
Most other known vendors, still consider 12 bit Oscilloscope as huge BIG THING, and their pricing policy this is still unreasonable.

Few Chinese vendors, they did release 12 bit Oscilloscope, but my trust this is hard to be earned from brand names which does not have a serious European based network for sales and products support.

[Kiriakos GR]

Fourteen months later and my enthusiasm in favor of TA189 AC/DC oscilloscope current probe, its still alive. 

In the world of digital power meter analyzer with 16 bit ADC, this TA189 it can deploy it full potential.
a) 16 bit ADC this has much lower noise floor.

b) TA189 AC/DC this has 100 KHz bandwidth, that is DC bandwidth of (medium in price range) digital power meter analyzer, and it can be used will all instruments which supporting EXT BNC input for a clamp probe.

c)  PICO Technology TA189, this probe has an history background as a product developed due a German and English collaboration.
ODM this GMC-I PROSys ltd, product model CP35.
And even Rohde & Schwarz liked this product design, and distributes it with model number R&S RT-ZC03 ( R&S HZC50 ).

Even within 2024, the technology in use at TA189, CP35, RT-ZC03, this is best in class as medium priced clamp probe.
Strong points: Measuring sensitivity, Noise immunity along 100 KHz bandwidth. 

The better clamp probe Class, are the ones priced at 5000 Euro or higher.
These has a more complicated electronic design, they require external PSU, they come at bandwidth of 50 MHz and 100 MHz.
They are tools for very specific needs regarding measurement and R&D.   

September 2024, I am exploring again all latest offerings as (medium in price range) digital power meter analyzer.
Any instrument not including EXT input, this gets out of my list of candidates. 

[Kiriakos GR]

This period of time I have started a new series of tests, of Low current ACA measurements at 50~400Hz.

Now I own my fresh Low-Current AC bench-top power meter, this able to measure since 1mA up to 2A.
My need is to observe AC Current waveform, and to also confirm due my oscilloscope the measurement.

I am using as first DUT my FLUKE 8846A:
Soft power OFF =  55mA  at 240V
Display On =  90mA at 240V   
   

By connecting TA189 probe at my GDS-2102A, I did notice that AC current measurement this was full of noise.
This time I am not using any current coil amplifier, as boost of current measurement.
This time I have to deal with Oscilloscope Noise floor along of probe noise floor. 
 
--------------------------------------------------------------------------------------

Today I have good news to share 
GW Instek GDS-2102A, this has a feature hidden at Acquire tools menu.
This is a adjustable digital bandwidth filter, by activating and adjusting this to 500Hz or up to 1000Hz as pass band, TA189 measurements they are now stable and comparable to my AC bench-top power meter. 

I also succeed to confirm, in this combination of Scope + Digital Low pass filter + Probe,  that the probe measurement range this is since 10mA AC and higher.         
--------------------------------------------------------------------------------------
Rohde & Schwarz GmbH & Co. KG, they sale RT-ZC03 (TA189).

I am now going to spy R&S oscilloscopes documentation, so to discover any application examples, or best advice's at using Digital Low pass filter.   

It is unfortunate, R&S RT-ZC03 User manual this does not provide any connectivity tips with an R&S scope.
Therefore I will have to do a deeper search of my own.


And now the bad news, if you do not own a medium range of oscilloscope, this loaded with such special features from the factory, you will never be able to use Low-Current precision probes. 

[Kiriakos GR]

R&S®RTC1000  -> Acquisition Setup  -> FILTER

Activates a low pass filter with adjustable cut-off frequency to sup-press unwanted high frequency interference's.
The cut-off frequency depends on the sampling rate.
Turn the universal knob to adjust the cut-off frequency.
The minimum setting is 1/100 of the sampling rate and the maximum value is 1/4 of the sampling rate.

[Kiriakos GR]

Now its time for a final confirmation under another one test.
Tested condition at ACA with Oscilloscope & DUT = Copper transformer =  Inductive load with core saturation

Verdict: At the specific application at AC 50/60Hz mains, TA189 sensitivity specification, this become different.
Current sensor and probe electronics, they deliver a working range this starting from 40mA.
With the addition of 5X boost coil, TA189 this becomes now able to measure reliably since 10mA AC and above.

In the combination of oscilloscope and current probe, at AC we need to measure the electrical quantity, and to also inspect the waveform visually. 
For a first time I also confirmed that my GDS-2102A, this also activates automatically LF bandwidth filter when input signal amplitude this is very low.

-> Acquisition Setup  -> FILTER: This is additional filter, that my scope also haves.
This serves for removing noise from a captured waveform, its like a visual aid.

Due trial and error, I did discover of what works best at my scope, I switched the trigger system to AC, now the scope uses the AC mains 50Hz as a known parameter.
Now even smallest signal quantity this appears stable on screen.
Now even when signal amplitude this increases or decreases, the measuring system this is constantly working, because the trigger this is never lost. 
The only downside, this is that GW Instek this forgot to add Auto-range at my scope. 
I have to switch V/Div manually, when input signal amplitude this is greater than the range.

When you have a known DUT current range, you may setup highest needed V/Div, and due Statistic measurement, this will record Min/Max levels too.

[overvolt]

So they are different sensitivity levels between hall effect sensor and CT sensor. 

Can you test the U1272A at it programmable conversion mV/A mode?
I wish to see the delivered digits resolution at 55mA AC.
Does the AC Low-pass filter makes any difference ?  (measuring stability)   

[Kiriakos GR]

I have here one last detail this puzzling my brain cells.
This is Typical output noise level this is offered exclusively at R&S datasheet, this be as 200uV RMS.
My scope this cannot confirm this measurement, actual typical noise this is much higher.
 
Just for sanity check, I did activate my PAC12 probe, and set both probes side by side.
Typical output noise level for PAC12 this is offered in detail by Chauvin Arnoux documentation.
And I successfully confirm it due my scope (Time division 1mS / 1KHz), with both probe powered and with out conductor in the jaws.
PAC12 in bold numbers:  3.5mV  RMS / 12mV PP  at 10mV/A   
TA189 in bold numbers: 1.37mV RMS /  7.8mV PP at 100mV/A  (both probes after zero adjustment).

Yes TA189 typical output noise level, this is a very low number, and a very strong point in favor of the product.
But R&S documentation this seems closer to what a DMM this can measure as Typical output noise level.
Attached relative screenshot ( scope + Typical output noise).   

Attached, U1272A DMM test, with Current scale mode active, Range 300mV, and at 30mV = best accuracy.   
DMM Range 300mV this deliver slower update speed = more easy to read.
My AC Mains line this is clean, DMM filter this does not make any difference.
Average typical noise at DMM with scale mode:  1.2mA  / Min 0.97mA / Max 1.71mA
Under this setup, it is confirmed the 5mA ~ 30A as TA189 operational range at any current waveform shape.

Oscilloscope & TA189 operational range this changes when waveform this is complex and not a clean sine wave (of a resistive load).
40mA ~ 30A this is the new usable operational range.
One add-on 5X coil this restores the operational range to 10mA~30A when the current this has a complex waveform.

[overvolt]

This is an excellent and complete product demonstration!

TA189 this comes very close to be a substitute of a leakage current clamp meter. 

Thanks  mate!   

[Andrew-88]

What I enjoyed the most, this is the tour within a serious lab. 

Everything in the lab this operating within it factory calibration, it was simply a matter of time so Kiriakos to complete this journey.
TA189 and U1272A, this is a very successful marriage!!
TA189 and GDS-2102A = Power quality verification and measurements
TA189 and 8846A = Endless quality control DUT testing, at high precision

TA189 = Europe