Introduction to Automotive Oscilloscopes (PicoScopes)
Automotive Oscilloscope Kits
that contain a PicoScope
|4225 2-Channel PicoScope Kits|
|4225 Starter Kit||4225 Standard Kit|
|4425 4-Channel PicoScope Kits|
|4425 Starter Kit||4425 Standard Kit|
|4425 Diesel Kit||4425 Engine and Hydraulics Kit|
|4425 Advanced Kit||4425 Master Kit|
|NVH Essentials Kits|
|4823 8-Channel PicoScope Kit|
|4823 Professional Kit|
An Automotive PicoScope turns your laptop or desktop PC into a powerful diagnostic tool. Think of it as the X-ray machine of diagnostics, letting you see the changing signals inside wires.
In order to use our automotive oscilloscopes, you will need a PC and some test leads to connect to the vehicle. Most people purchase one of our award winning Automotive Diagnostics Kits. These money-saving kits contain everything you need. Please consider our 2 Channel or 4 Channel Starter or Diagnostic Kits or our more advanced kits (listed above) rather than purchasing the oscilloscope on its own.
Consider our 4-channel Automotive Oscilloscope Kits
Our 2-channel 4225 Automotive Oscilloscope is a really good choice for specific applications that need only 2 channels as well as for those with budgetary constraints. However, please consider choosing the 4-channel 4425 Automotive Oscilloscope or a kit that contains it, because it is far more useful and a better long-term investment. Kits can be upgraded by purchasing extra components but a 2-channel scope cannot.
We can also supply you with a range of suitable desktop and laptop PCs. You can use any suitable Windows-based laptop or PC that you may have.
These items are usually supplied with your PicoScope when it is bought on its own. When you purchase a kit containing a PicoScope, these items are included.
- USB Cable
- User Manuals
- Software CD-ROM
See the new 4823 8-Channel Automotive Oscilloscope and the 8-Channel Professional Kit click here for more details on the new oscilloscope or click on the Specifications Tab below.
What is an Automotive Oscilloscope and why do I need one?
An oscilloscope (scope) is a simple device. All it does is draw a graph of a value (e.g. voltage, current, pressure, sound) vs time. The PicoScope is a storage scope so it draws the graph (actually up to four at the same time) and remembers it so that you can study what happened after the event occurs.
How does the Automotive Oscilloscope know when to draw the Graph?
By default, the Automotive Oscilloscope draws graphs continuously. This happens when no trigger is defined (none).
You can configure your PicoScope to start drawing a graph when it is triggered. Some event occurs e.g. an injector closes (see right), the cam sensor detects TDC, the ignition key is turned, the headlights are turned on - you decide. The scope draws the graph and you can analyse what happened.
Being a storage scope, the Picoscope has another huge advantage, it continually monitors what is happening and stores and displays the graph as soon as it is triggered. This means that it can even display what happened before it was triggered. Think of a DSTV Explora or PVR Decoder which allows you to rewind live TV. Your PicoScope allows you to look back in time and find out what caused the event.
Can I control what I see?
Absolutely! You can decide how long the scope records for and how much detail you want. You can filter the graph to highlight certain events or problems and change the scale. You can even compare your graph with other similar graphs to highlight any differences to help you identify faults. PicoScopes have libraries of waveforms that you can access.
The trace in the case study below shows 70% of the display is dedicated to time before the trigger. You can choose where to place the trigger on the display.
Why is a PC necessary?
Your Picoscope uses a PC or laptop computer as its display. This has many major benefits. PCs have high resolution displays and lots of storage. You can examine your waveforms in minute detail and save them to create a knowledge-base. You can email them if you need help and compare them to waveforms downloaded from the Internet. Print your test results to show your customers where problems were and how they were solved. You can watch training videos, follow test set-up instructions and access our comprehensive Help to increase your efficiency.
Whilst the PicoScope is a sophisticated data capture system with many functions and features, it does not have any controls. You can simply think of it as the place to plug in your test leads. You only interact with the PC and everything is controlled from there.
When you buy a PicoScope, you only pay for an instrument optimised for automotive diagnostics. Oscilloscopes with built-in high quality displays are very expensive. PCs are optimised for storage, processing, communication and display. We believe in giving you the choice, PicoScope allows you to build a diagnostic system that suits your business.
I use a multi-meter, why do I need a PicoScope?
A multi-meter can measure static values such as the battery voltage, current through a lamp, resistance of a coil and continuity. A PicoScope can show how things change. It can also measure things that happen very quickly, such as spikes, ignition pulses, etc.
The new Automotive PicoScopes have a bandwidth of 20MHz (20 million cycles per second) and a sampling rate of up to 400 million samples per second. 250 million samples of 4,096 levels can be accommodated in its buffer. A multi-meter has many applications but cannot replace the functionality of and insight provided by a PicoScope.
The PicoScope has enormous storage capability and can also be used to look at things that happen very slowly (e.g. hours). Find that elusive, intermittant fault by looking back through the PicoScope's waveform buffer.
How do I connect the scope to the vehicle?
Injector Voltage and Current Case Study
The display shows the voltage across an injector and the current flowing through it.
Analysing the Waveform
A true understanding of a vehicle's engine comes from experience and the ability to see and understand what is happening. Your PicoScope provides that ability. As you use the product, your understanding will grow naturally and we believe that you will find it indispensable.
The Injector Opens
The blue trace (voltage 8V) went low when the injector was switched on. The current started to increase and was limited to about 1 Amp (the flat top on the current waveform probably by the coil resistance of about 8Ω).
The Injector Closes
The injector was switched off and the scope was triggered (yellow diamond) by that event. The collapsing current in the inductor (the coil in the injector) generated the spike at the end but the voltage was clamped (flat top on the voltage spike) at just under 30V which protected the injector driver (i.e. the electronic switch).
Analysing the Injector's Mechanics
Certain inferences can be drawn from electrical signals that can reveal the operation of mechanical components.
When the injector opens and closes, its inductance changes which affects the current (and voltage). The small increase in the current slope at about -0.8 ms (A millisecond ms is a thousandth of a second) would have been caused by the injector physically starting to open. The next increase (-0.6ms) resulted from the injector being fully open. The injector started closing at 0.0ms (because the current was switched off) and the small 'bump' in the voltage (0.2ms) as it collapses would have been caused by the injector physically closing. This means that the injector took about 0.3ms to start opening, 0.2ms to open and to close and was open for about 1ms (-0.8 to 0.2ms) and fully open for about 0.6ms (-0.6 to 0ms).
The power of the PicoScope and the importance of this level of analysis is demonstrated in the Peugeot 406 Case Study.
This trace shows simultaneous display of voltage and current. It also show how the scope recorded what happened, prior to being triggered.
This waveform was derived from the "demo device" in PicoScope 6 Automotive Software. You can download this software, free of charge, from the PicoAuto website download page and try it out for yourself. For this example, use (200μS/div), Channel A (10x probe, ±50V) for the injector voltage and Channel B (6A Current Clamp - 20A mode, ±2A) for current.