Scope and Multimeter Introduction
This section describes the basic operation and navigation of the Scope Multimeter function.
Selecting Scope Multimeter provides access to all the tools needed for performing electrical circuit tests and monitoring signals. The Scope Multimeter function works interactively with other functions. Selecting “View Meter” from a Guided Component Test or Scanner Test opens the Scope Multimeter function.
In situations where the testing connection points are not easily accessible, the Scope Module easily separates from the diagnostic tool (connected via extended length USB cable) allowing you to monitor the results remotely.
Risk of electrical shock.
Read the Safety Information provided for important warnings on the use of this product
This product is intended for low voltage systems (for example, automotive 12V systems), do not use this product for Measurement Categories II, III, and IV.
This product is designed for performing measurements on circuits not directly connected to MAINS or MAINS circuits (an example of a MAINS circuit is 120V AC or 240V AC household or industrial electricity), do not connect this product to MAINS or MAINS circuits.
Do not apply the Black Ground Lead to test points other than ground/system return/vehicle chassis.
Electrical shock can cause personal injury, equipment damage, and/or circuit damage.
Maximum rated transient over voltage impulse is 500 volts, do not exceed the rated transient over voltage.
A group of arrows display when a measurement is out of range for the scale selected:
● | Arrows pointing UP—measurement over maximum range |
● | Arrows pointing DOWN—measurement under minimum range |
Voltage measurements also display arrows in place of live values when the voltage exceeds the input rating of the meter.
Risk of electrical shock.
Do not exceed voltage limits between inputs as indicated on the rating label.
Use extreme caution when working with circuits that have greater than 40 volts AC or 24 volts DC.
Electrical shock can cause personal injury, equipment damage, and/or circuit damage.
If arrows are displayed in the live voltage values, discontinue circuit testing.
Correct an out-of-range condition by selecting a scale setting appropriate for the signal being sampled. See Trace Controls Menu for more information.
1. | Auxiliary (DB9) Connector The auxiliary connector is used for connection of the optional RPM inductive pickup and the pressure transducer split lead adapter. For additional information contact your sales representative. |
2. | B Type USB Jack - Used to connect the scope module to the diagnostic tool using the supplied A/B type USB cable. |
3. | Common (Ground) Jack) |
4. | Channel Jacks 1 to 4 |
Strap and clip on back of Scope Module - Used to hand the module, or for cable storage.
The following chart lists the available DMM, GMM, and Lab Scope tests.
Not all the tests listed are described in this manual. This list is intended as reference only.
DMM |
GMM |
LS |
Test |
Function |
|
|
X |
Four Channel Lab Scope |
Displays four Lab Scope channels automatically. |
|
X |
|
Four Channel Graphing Meter |
Displays four Graphing Multimeter channels automatically. |
|
|
X |
Ignition Probe |
Measures secondary Ignition voltage 2 to 50kV. Displays secondary ignition (kV) waveforms. |
X |
X |
X |
Volts DC |
Measures DC (direct current) voltage. DC voltage is measured through test leads connected to a DC circuit. |
X |
X |
|
Volts DC - Average |
Measures DC voltage using a filter to determine the average voltage over a period in time. DC voltage is measured through the two test leads connected to a DC circuit. |
X |
X |
|
Volts AC RMS |
Measures the effective AC voltage, not the peak voltage which results in measurements with higher accuracy. The AC RMS (root mean square) voltage value can be defined as the equivalent DC voltage of the AC voltage measured. RMS values are commonly used in AC electrical measurement, as they are more representative of DC measurements. |
X |
X |
|
Ohms |
Measures electrical resistance (opposition to current) 0 to 4 M Ohms. Scope supplied DC current is passed through the circuit to measure the resistance between the two connected test leads. |
X |
|
|
Diode/Continuity |
Measures voltage drop across a diode and continuity through a diode. Scope supplied DC current is passed through the diode to measure the voltage drop between the two connected test leads. Typical setup for positive to negative current flow - positive lead (anode +/side) and negative (cathode -/side). |
|
X |
|
Frequency |
Measures the number of times a signal repeats itself per second. Used to measure frequency of signals such as CKP, CMP and wheel speed sensors. |
|
X |
|
Pulse Width |
Measures the on-time of various components |
|
X |
|
Injector Pulse Width |
Measures fuel injector on-time when checking for variances when engine load is changed and/or physical problems with the injector. |
|
X |
|
Duty Cycle |
Measures the ratio of the pulse width to the complete cycle width, the on-time of components that cycle on and off like EGR, or canister purge from 0–100%. |
X |
X |
X |
Low Amps (20) |
Used to measure amperage of typical devices (e.g. ignition coils, injectors, fuel pumps) that may draw up to 20A peak (startup) when initially started. Also used to measure parasitic draw. |
X |
X |
X |
Low Amps (40) |
Used to measure amperage of typical motors and devices that may draw up to 40A peak (startup) when initially started. |
X |
X |
X |
Low Amps (60) |
Used to measure amperage of larger motors and devices that may draw up to 60A peak (startup) when initially started. |
|
X |
|
MC Dwell (60) |
Measures carburetor Mixture Control Solenoids (0–60°). The duty cycle of the solenoid is expressed in the dwell angle of a 6 cylinder engine: 100% = 60 deg. |
|
X |
|
MC Dwell (90) |
Measures fuel system Mixture Control Solenoids (0–90°). The duty cycle of the solenoid is expressed in the dwell angle of a 4 cylinder engine: 100% = 90 deg. |
|
X |
X |
100 PSI Vacuum |
Used to measure vacuum up to 20 in.Hg, using the 0–100 psi transducer. |
|
X |
X |
100 PSI Pressure |
Used to measure pressures for typical systems such as, fuel, oil, EVAP, hydraulic/transmission fluid etc. up to 100 psi, using the 0–100 psi transducer. |
|
X |
X |
500 PSI Pressure |
Used to measure pressures for typical systems such as, hydraulic/transmission fluid pressure, cylinder compression, and AC high side up to 500 psi, using the 0–500 psi transducer. |
|
X |
X |
5000 PSI Pressure |
Used to measure pressures for typical systems such as, ABS, power steering, and heavy-duty hydraulic system fluid up to 5000 psi, using the 0–5000 psi transducer. |
The digital multimeter gives you the ability to quickly make precise common electrical measurements (e.g. DC and AC voltage, resistance and amperage) on circuits and components to verify operation. The meter displays measurements in a digital numerical format, and is typically used for measuring signals that are not rapidly changing.
The DMM is ideal for performing basic tests on most standard automotive circuits, and displays the results in a large easy to see format.
To use the DMM, select the Scope Multimeter icon from the home screen, then select Digital Multimeter from the menu. See Tests and Capabilities (Quick Reference Chart) for a list of available testing functions.
Function |
Range |
Accuracy/Comments |
Signal Measurement |
Ch. 1—yellow jack |
Channel 1 input is referenced to common ground (GND—black jack) |
VDC (Full Scale) |
75VDC |
Do not measure greater than 75VDC |
VAC (Full Scale) |
50VAC |
Do not measure greater than 50VAC (rms) |
Signal Measurement Input Impedance |
10 MΩ |
- |
Ohm Measurement Diode Test Continuity Test |
Ch. 3—blue jack |
- |
Ohms |
40 Ω–4 MΩ |
Fixed scales or Auto Ranging |
Glitch capture |
Approximately 50 uS |
- |
Diode Test |
2 V Scale |
- |
Unlike the DMM, the graphing multimeter plots a visual graphing line of the signal instead of displaying digital values. The GMM displays a signal’s measurements over time on a two-dimensional grid. This plotted graph is basically a graphical history (histogram) of the signal’s measurements over time.
The GMM uses a higher sample rate (than a DMM) to calculate signal measurements. This characteristic along with the visual graph, make the GMM ideal for finding intermittent dropouts or glitches that may not be obvious when viewing a digital value. A key advantage of the GMM is being able to capture a signal over a long time interval and then review it’s graphical history, to visually see if and when dropouts have occurred.
In addition, the GMM uses a combination of filter and peak detect modes to provide a good balance between detecting fast glitches and preventing unwanted noise from displaying.
Unlike the lab scope, the sweep scales used with typical GMM tests are of longer time intervals, and may range from seconds to minutes, compared to the lab scope sweep scales that use relatively short time intervals (e.g. milli and microseconds). This allows you to monitor a signal over a longer period of time when looking for erratic glitches or dropouts.
To use the GMM, select the Scope Multimeter icon from the home screen then select Graphing Multimeter from the menu. See Tests and Capabilities (Quick Reference Chart) for a list of available testing functions.
Function |
Range |
Accuracy/Comments |
Signal Measurement |
Ch. 1—yellow jack |
Each channel input is referenced to common ground input (GND—black jack) |
Sample Rate |
1.5 MSPS |
Continuous sampling, |
Bandwidth |
DC–3 MHz |
3 db point @ 3 MHz |
Input Impedance |
10 MΩ@ DC |
Channel 1–4 |
VDC (Full Scale) |
75VDC |
Do not measure greater than 75VDC |
VAC (Full Scale) |
50VAC |
Do not measure greater than 50VAC (rms) |
Ohm Measurement Diode Test Continuity Test |
Ch. 3—blue jack (-) |
- |
Ohms |
40 Ω—4 MΩ |
Fixed scales |
Low Amp Probe |
20A scale (100mV/Amp) |
Connect the positive (+) Amp Probe lead to the yellow jack on the diagnostic tool for values on Ch.1, or to the green jack for values on Ch. 2. Connect the negative (–) lead to GND (black jack)1. |
1 Do not use the Low Amp Probe to measure current on conductors at a potential greater than 46VAC peak or 70VDC. |
Similar to the GMM, the lab scope (oscilloscope) plots a visual image line of a signal’s measurements over time on a two-dimensional grid. The visual line that is displayed is commonly called a trace, and the graphical form created by a signal is called a waveform.
Unlike the DMM the lab scope allows you to visually see a signal’s waveform, which in turn allows you to see the strength and shape of the signal, as well as any noise that may be occurring in the circuit. The lab scope also samples signals at a high rate, which allows you to see a higher level of detail in shorter samples of the signal, especially in signals that change rapidly. In addition, the lab scope also provides more control over the acquisition of the signal and in how it is displayed through the use of triggers and channel controls. All of these features allow you to analyze signals in great detail when performing diagnostics.
To use the lab scope, select the Scope Multimeter icon from the home screen then select Lab Scope from the menu. See Tests and Capabilities (Quick Reference Chart) for a list of available testing functions.
Function |
Range |
Accuracy/Comments |
Signal Measurement |
Ch. 1—yellow jack |
Each channel input is referenced to common ground input (GND—black jack) |
Sample Rate |
For 50uS sweep 6MSPS |
Continuous sampling, |
Bandwidth |
DC–3 MHz |
3 db point @ 3 MHz |
Input Impedance |
10 MΩ@ DC |
Channel 1–4 |
VDC (Full Scale) |
100mV–400V |
Do not measure greater than 75VDC |
VAC (Full Scale) |
100mV–400V |
Do not measure greater than 50VAC (rms) |
Low Amp Probe |
20A scale (100mV/Amp) |
Connect Low amp Probe (+) to Ch. 1 (yellow jack) and (–) to GND input (black jack)1. |
1 Do not use the Low Amp Probe to measure current on conductors at a potential greater than 46VAC peak or 70VDC. |
200V to 400V scales are not to be used to measure signals greater than 50VAC (rms) or 75VDC. Do not use the Scope/Meter to measure greater than 50VAC (rms) or 75VDC.