PicoScope 2205A Oscilloscope and Attenuators

Greetings Readers,

I am not attacking Pico since they provide excellent YouTube videos, Website tools and products. I am simply asking questions to better understand the product.

I am still new to this forum. Recently I purchased a PicoScope 2205A Oscilloscope from an Automotive Diagnostician from his Amazon store.

Finally, I thought is an affordable oscilloscope for at home DIY mechanic to work on newer cars that requires a scope to see Body Control Module, Transmission Control Module, fuel pump, and electronic products installed on the vehicle. I downloaded both Pico 6 (Basic for automotive) and 7 software. Upon looking at my PicoScope 2205A Oscilloscope model, Pico says it is not an automotive device and I can not access the waveform library.

1) Why did Pico design this oscilloscope, which is expensive, and not for automotive. I have seen some people used it with PicoScope 6 software.

2) Attenuators: I understand that the high voltage measurements can damage the oscilloscope without the attenuator installed. 10:1 or 20:1 attenuator.

3) Which should I buy and use the 10:1 or 20:1 attenuator and how many? Do we use it on all channels with the BNC cables, two in my case?

4) Why will Pico not release the Waveform Library to any Pico device owners?[/list]

One YouTube video explained only the 20:1 attenuator about distorting the waveform and it's function to reduce voltage 20X. So in this instance, do we not use the attenuator when measuring less than 20 V, for my device, but how to we prevent surges over the 20V limit?

Thank you in advance for your reply. Your time is greatly appreciated.

Judo64 wrote:

Greetings Readers,
I thought is an affordable oscilloscope for at home DIY mechanic to work on newer cars that requires a scope to see Body Control Module, Transmission Control Module, fuel pump, and electronic products installed on the vehicle.

You do not need a scope to access Body Control or Transmission control modules. You need a suitable scantool.

I downloaded both Pico 6 (Basic for automotive) and 7 software. Upon looking at my PicoScope 2205A Oscilloscope model, Pico says it is not an automotive device and I can not access the waveform library.

1) Why did Pico design this oscilloscope, which is expensive, and not for automotive. I have seen some people used it with PicoScope 6 software.

You've answered your own question. Pico has a wide variety of oscilloscopes, designed for different areas of electronics. The automotive industry is just on of those areas. The 2205A is not designed for Automotive use. However, it can be used for many things in the automotive industry. You will need to learn the limitations of the scope that you are using. Pico 2000 series specs.

2) Attenuators: I understand that the high voltage measurements can damage the oscilloscope without the attenuator installed. 10:1 or 20:1 attenuator.

3) Which should I buy and use the 10:1 or 20:1 attenuator and how many? Do we use it on all channels with the BNC cables, two in my case?

This is why you need to know the limitations of your scope. The Specs for the 2000 series say that the input range is +/- 20 volts. This is fine for most automotive circuits/signals. But keep in mind that solenoids and coils produce voltage spikes. An injector might spike to 150 volts. A 10:1 attenuator would knock that spike down to 15 volts (150/10=15), well within the specs of the scope. However, an ignition coil can spike upwards of 400 volts. A 10:1 attenuator would only knock that spike down to 40 volts (400/10=40), which is higher the what the 2000 series is rated for (the 2000 series has over-voltage protection up to 100 volts. ) You would need a 20:1 attenuator to knock a 400 volt spike down to 20 volts (400/20=20).

4) Why will Pico not release the Waveform Library to any Pico device owners?[/list]

I can't speak for Pico, but my guess is because of the extra research and developement that is required to produce and maintain the Waveform library and Automotive Specific testing software. They could not support these valuable resources without the revenue from the Automotive line of scopes.

One YouTube video explained only the 20:1 attenuator about distoring the waveform and it's funtion to reduce voltage 20X. So in this instance, do we not use the attenuator when measuring less than 20 V, foe my device,

That is correct. For signals less than 20 volts, no attenuator is needed.

but how to we prevent surges over the 20V limit?

Know your circuit. Understand what you are testing. Anything that creates a magnetic field ( i.e. solenoids, relays, injectors, ignition coils), will create a voltage spike when the magnetic field collapses. The size of the spike depends on the magnetic field created. VRS sensors produce signals of varying voltages. Sometimes, they can easily exceed 20 volts.

@ Chad

Thank you for your reply. It is clear now from your explanation. PICO is a good company. I thought the PicoScope 2505A Oscilloscope could be used with PicoScope 7 software when I originally bought the product because of it's price point. I am beginning to see its limitation for automotive testing.

I just need to see the Camshaft/Crankcase Position Sensors that you can not test with a simple voltmeter. I have Launch Scanner that tells me the same thing as my codec reader minus the bi-directional function. The only thing it lacks for my car is the Camshaft/Crankcase Position Sensor Relearn function.

Thank you very much for your input--a learning experience for me and others who might not be familiar with those products. Your explanation on the attenuator was spot on how to calculate to use with electrical components. That is why I delayed on testing with my oscilloscope until I obtain the right attenuator.

Again thanks!!!