Lab Scope Voltage Limits

[phill57]

Good day everyone I trust your'e off to a productive start into 2023.

I have a question regarding the maximum voltage the Verus Edge scope can handle. On the back the the scope module it shows 50V AC and 75V DV as max. I know when scoping a primary ignition waveform the voltages can peak at 200 to 300 volts due to the magnetic field collapse. One of my YouTube viewers asked me if we should be using an attenuator and I really could not answer him. I do note the scope and multimeter limits can go as high as 400V DC. Maybe it has a built in antennuator?

[Wheel]

Originally Posted by phill57

Good day everyone I trust your'e off to a productive start into 2023.

I have a question regarding the maximum voltage the Verus Edge scope can handle. On the back the the scope module it shows 50V AC and 75V DV as max. I know when scoping a primary ignition waveform the voltages can peak at 200 to 300 volts due to the magnetic field collapse. One of my YouTube viewers asked me if we should be using an attenuator and I really could not answer him. I do note the scope and multimeter limits can go as high as 400V DC. Maybe it has a built in antennuator?

I can't answer your question, but for no more than this https://www.aeswave.com/Primary-Igni...PRO-p8792.html costs, I would call it cheap insurance and a useful addition to any Snap on scope user's arsenal. They've got a lot of handy stuff to help get more from your Snap On scope.

[Tech_A]

Originally Posted by phill57

Good day everyone I trust your'e off to a productive start into 2023.

I have a question regarding the maximum voltage the Verus Edge scope can handle. On the back the the scope module it shows 50V AC and 75V DV as max. I know when scoping a primary ignition waveform the voltages can peak at 200 to 300 volts due to the magnetic field collapse. One of my YouTube viewers asked me if we should be using an attenuator and I really could not answer him. I do note the scope and multimeter limits can go as high as 400V DC. Maybe it has a built in antennuator?

50V AC and 75V DV are the working voltages. Direct injectors can get up to 60+ volts DV. Do not try to measure the output of high-voltage systems. The tool does not have a built-in attenuator.

400V is the display scale for the lab scope, this should handle most primary ignition signals, injectors, and high-pressure fuel pump solenoids.

For secondary ignition measurement, there are adaptors available.

Examples

Ford Multistrike with Amp testing
https://www.youtube.com/watch?v=Pw1E...-onDiagnostics

Direct Injection
https://youtu.be/uhzXP9qWmZ4?t=884ht...XP9qWmZ4?t=884

refer to additional warnings in the user manual
https://www.snapon.com/display/3871/...UserManual.pdf

[Brembo30]

I'm the guy who asked the question...
I understand what you're saying regarding the written instructions about the m4 scope, i read it myself. Ok...don't use above 50/75v...but this scope has been on the market basically unchanged for the last +10 years. On YouTube there are hundreds of videos where primary ignition waveforms are captured not using an attenuator.
Just set on 400v scale and capturing +300v spikes.

The question was...what's the technical explanation on why you can push it 6-8 times the limit without burning it?

Not even snap-on sells an attenuator for it's automotive designed scope...

[Rich Shepherd]

Originally Posted by Brembo30

I'm the guy who asked the question...
I understand what you're saying regarding the written instructions about the m4 scope, i read it myself. Ok...don't use above 50/75v...but this scope has been on the market basically unchanged for the last +10 years. On YouTube there are hundreds of videos where primary ignition waveforms are captured not using an attenuator.
Just set on 400v scale and capturing +300v spikes.

The question was...what's the technical explanation on why you can push it 6-8 times the limit without burning it?

Not even snap-on sells an attenuator for it's automotive designed scope...

The Scope Multimeter is rated as a Category (CAT) 1 device designed to handle the voltages present on a standard 12V vehicle.
Although the voltages that power a typical vehicle are normally between 12 and 24 volts, there are components that can cause temporary voltage spikes that exceed these voltages. The primary ignition circuit and the fuel injector circuits, which rely on electro-magnetic coils, can cause voltage spikes that can exceed 100 Volts for a short period (microseconds or milliseconds) and have limited energy.
While the Category I Snap-on devices are rated for a maximum of 50 Volts (AC) and 75 Volts (DC), they are designed to safely withstand and display those temporary inductive driven voltage spikes (Up to 400V on the highest range).

[Brembo30]

Originally Posted by Rich Shepherd

The Scope Multimeter is rated as a Category (CAT) 1 device designed to handle the voltages present on a standard 12V vehicle.
Although the voltages that power a typical vehicle are normally between 12 and 24 volts, there are components that can cause temporary voltage spikes that exceed these voltages. The primary ignition circuit and the fuel injector circuits, which rely on electro-magnetic coils, can cause voltage spikes that can exceed 100 Volts for a short period (microseconds or milliseconds) and have limited energy.
While the Category I Snap-on devices are rated for a maximum of 75 Volts (DC), they are designed to safely withstand and display those temporary inductive driven voltage spikes.

So basically what is the effective limit of the scope when used on short peak voltages?
I'm guessing we are talking about peak to peak voltages versus sinusoidal signal which makes sens because it's a different kind of measurement.
Why wouldn't the manufacturer put also this peak voltage on the spec sheet?
I have an old fluke 192 with 500v cat III written on the back which I guess means 500v rms but it's not very user friendly for automotive work.

[Tech_A]

Originally Posted by Brembo30

So basically what is the effective limit of the scope when used on short peak voltages?
I'm guessing we are talking about peak to peak voltages versus sinusoidal signal which makes sens because it's a different kind of measurement.
Why wouldn't the manufacturer put also this peak voltage on the spec sheet?
I have an old fluke 192 with 500v cat III written on the back which I guess means 500v rms but it's not very user friendly for automotive work.

the device can measure up to 400v

Spec sheet is available here
https://www.snapon.com/display/1068/...dgeBidSpec.pdf

[Brembo30]

Originally Posted by Tech_A

the device can measure up to 400v

Spec sheet is available here
https://www.snapon.com/display/1068/...dgeBidSpec.pdf

I'm pretty sure that if you put 400v DC directly to the input the warranty will say "what?! It's written 75v max on it!" )

[spinellib]

I've been curious about this, too.

But maybe the question we should be asking is: Anybody ever fry their SO scope? Surely it must've happened. If so, it would be nice to know the circumstances.

There's always one or two M4 scope meter modules for sale on ebay. I always wonder WHY someone would need to replace their M4 modules -- did they fry their original module, or lose it, or drop it, etc?

[Rich Shepherd]

Originally Posted by Brembo30

So basically what is the effective limit of the scope when used on short peak voltages?
I'm guessing we are talking about peak to peak voltages versus sinusoidal signal which makes sens because it's a different kind of measurement.
Why wouldn't the manufacturer put also this peak voltage on the spec sheet?
I have an old fluke 192 with 500v cat III written on the back which I guess means 500v rms but it's not very user friendly for automotive work.

Please see my updated post above.