Floating and isolated inputs on 3 and 4 thousand series?

Ask any questions relating to the PicoScope hardware or kit contents here.
If you have any questions prior to purchasing the kit post them here.
Post Reply
Basil
OneWave
OneWave
Posts: 14
Joined: Tue Aug 09, 2011 9:01 pm

Floating and isolated inputs on 3 and 4 thousand series?

Post by Basil »

Do the 3000 and 4000 series automotive scopes have fully isolated and floating inputs on all channels? Thanks. A healthy and prosperous New Year to all,

User avatar
Autonerdz
TwoWaves
TwoWaves
Posts: 387
Joined: Wed Nov 20, 2002 4:19 pm
Location: Washington State USA

Re: Floating and isolated inputs on 3 and 4 thousand series?

Post by Autonerdz »

Basil,

The 3000 and 4000 automotive scopes have common grounds for the channels. So, when using more than one channel, all grounds should be referenced to the same vehicle ground to prevent a ground loop. It's also essential to ground the scope when using an attenuator as these need to be grounded to work properly and provide protection.

What was it you were wanting to do?
Tom Roberts
(The Picotologist)
Autonerdz

Basil
OneWave
OneWave
Posts: 14
Joined: Tue Aug 09, 2011 9:01 pm

Re: Floating and isolated inputs on 3 and 4 thousand series?

Post by Basil »

Hi Autonerdz, it was more a case of wondering if I needed to take car NOT to do something untoward. To be honest I am using a none automotive USB scope at the moment, a Dataman 526 model http://www.dataman.com/dataman-526-150- ... scope.html which is OK, but I am worried about blowing either it, or any vehicle ecu it's connected to, up. I am looking to buy a dedicated scope for automotive work, either USB or bench, as most jobs I do are in the shop, not out on the road. I have read that some USB and bench scopes have totally isolated and floating inputs, so I could measure say the cam sensor output of an engine on channel 1 and the AC mains at the wall outlet on channel 2 (to be ridiculous, and using an attenuator on channel 2) without risk of damage. I was wondering if the automotive Picoscopes had this. My knowledge of one of the odd ball vintage race ecus I get to look at is limited by what info is available, for some of the early stuff from Mugen and Zytek, this is not a lot. I'd hate to unknowingly create a ground loop and do one a mischief. Are floating, isolated inputs a good safety feature, or am I worrying needlessly? Thanks for your reply, a happy and healthy New Year to you.

User avatar
Autonerdz
TwoWaves
TwoWaves
Posts: 387
Joined: Wed Nov 20, 2002 4:19 pm
Location: Washington State USA

Re: Floating and isolated inputs on 3 and 4 thousand series?

Post by Autonerdz »

Are floating, isolated inputs a good safety feature, or am I worrying needlessly?
You are worrying needlessly. Isolated inputs are not needed for automotive work. However, if you do want to look at mains or the high voltage circuits of a hybrid vehicle, you will need to use a CAT III differential isolation probe.

The Pico automotive scopes do have thermal fuse protection should you inadvertently put grounds across a power supply. This prevents scope damage. I have never known of anyone to damage a vehicle from hooking up a scope. Worst case scenario, you might create a no start by grounding out a crank sensor or something.
Tom Roberts
(The Picotologist)
Autonerdz

Post Reply