An oscilloscope is a frequently used device in electric production and repair works. It is an important tool in the automotive industry due to its multiple facets.
A good automotive oscilloscope can be used to observe electric output signals, test sensors, or troubleshoot actuators.
It can also be used to determine primary and secondary ignitions or even communication data streams. In some cases, it can be used for engine management systems or brake and balance systems.
But to ensure proper use, it is important to know how to use automotive oscilloscope first.
Read on to learn more.
How to Use Automotive Oscilloscope
If you haven’t used an automotive oscilloscope before, now’s the time to learn.
Step 1: Learn to Read Oscilloscope Screen
An oscilloscope is essentially a voltmeter. In other words, it shows the fluctuation in voltage, which is then shown as a waveform on an oscilloscope screen.
So, to properly understand how to work with this crucial tool, it is crucial to learn to read an oscilloscope screen.
A typical oscilloscope screen is similar to a graph, where the horizontal x-axis represents time and the vertical y-axis represents voltage.
Change of voltage through time results in a visual representation of shape, amplitude, and frequency.
On the other hand, no change of voltage through time refers to the lack of electrical current source, which creates a straight line known as zero line, as it represents 0V voltage at the input of the oscilloscope.
Step 2: Adjust the Systems
An oscilloscope is made up of three major systems – horizontal, vertical, and trigger.
The control panel of an oscilloscope is sectioned into these three, so it is important to learn how to adjust the systems to use an oscilloscope properly.
Consists of three major controls – time base, zoom, and position.
Time base is the most important setting of the horizontal system, and it controls the rate at which the waveform is drawn across the oscilloscope screen.
Zoom magnifies different sections of the waveform.
Position allows lateral movement of the waveform across the screen to wherever it is required.
Consists of five major controls – position, range, coupling, invert, and polar control.
Position allows superior and inferior movement of the waveform across the screen to wherever it is required.
Range scales the size of the waveform and sets the highest possible voltage for display.
Coupling can be either AC or DC. When coupling is AC, the waveform is made up of only AC and no DC, which helps in zooming and measuring.
When coupling is DC, the waveform is made up of both AC and DC.
Invert displays the signal upside down.
Polar control, when unipolar, shows only positive values, and when bipolar, shows both positive and negative values.
Defines the moment the plot of a new waveform starts, and consists of five major controls – trigger level, trigger edge, pre-trigger, trigger type, and trigger source.
Trigger level provides basic definition of trigger point and displays waveform.
Trigger edge determines the slope and level of the signal which triggers the oscilloscope.
Pre-trigger helps in observing the rightwards shift of the signal on the horizontal axis.
Trigger type considers the continuous input signal offset. Trigger source allows the selection of the input channel responsible for the trigger.
Step 3: Choose Input Probe
An input probe is used to extend the input range of an oscilloscope to perform high voltage measurements.
So, it is important to choose one wisely, so that the input probe either matches or exceeds the bandwidth of the oscilloscope.
Commonly used input probes include coil-on-plug pickup clamps, inductive pickup clamps, voltage input attenuators, AC/DC current clamps, boost pressure sensors, common rail pressure sensors, pressure inducers, etc.
Step 4: Set to Automotive Pre-set
Automotive pre-set automatically sets all the different settings of an oscilloscope to base values.
Use it well to make measurement adjustments easier. Make edits to old pre-sets or create brand new ones if necessary.
Pre-sets are split into a number of categories, such as sensors, injectors, ignitions, diesel, electric systems, communication, etc.
Step 5: Use Measurement Markers
Measurement markers help determine the exact value on an oscilloscope screen, so it is a must to have proper knowledge about them.
In most automotive oscilloscopes, cursors are used as measurement markers.
Cursors pinpoint the value of time on the x-axis and value of voltage on the y-axis, and also note the difference between the values at the two points.
Simply click on the various parts of the graph that need to be measured, and there will be a placement of temporary static markers. When there are two markers, the divergence is displayed.
720-degree scale is another example of a measurement marker. It is used when two revolutions of the crankshaft are required.
720-degree scale is enabled via a click on the 720-degree button. It is expanded with a left-click and arrow drag. Any number of markers can be placed on any point on the screen.
It is important to note that measurement markers cannot be used when the measurement is run, but rather when the measurement is at a stop.
It is never easy to figure out how to use automotive oscilloscope as soon as you start, but it is harder if you never even bother to try.
So, pull the device out and plug it right in. Tinker with the options available. And most importantly, practice. Soon, you too will know how to best use an automotive oscilloscope.