Hi should I use attenuator when measuring piezzo injector with a currently probe, and is the new Pico TA197 10.1 attenuator compatible with older Picoscope that required TA010 20.1 attenuator?
Regarding attenuation, the TA197 10:1 attenuator has superseded the 20:1 TA010 model; could I ask which scope you are using?
Both the TA197 and TA010 are compatible with older scopes, however, we must be aware of the maximum input voltage of the scope.
For example, the 4423 scope has a max input of 100 V and therefore the 10:1 attenuator is fine for ignition primary circuits peaking at 500 V (500 / 10 = 50 V)
However, if you are using the 3423 or the 4823 the max input voltage is 50 V; and for ignition primary circuits peaking at 500 V you are on the cusp of exceeding the max input voltage of these scopes with a 10:1 attenuator. With that said, for the time the voltage peaks and 500 V and the minimal energy present you will be fine.
If you are using a 20 V max input scope, then additional attenuation would be required for primary ignition
Returning now to your measurements of Piezo injector voltage which can often exceed 200 V, you will be fine with the compatible TA197 10:1 attenuator for our older range of automotive scopes