benchtop:dmm

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benchtop:dmm [2020/03/06 15:03] – 128.61.124.70benchtop:dmm [2020/03/06 15:21] (current) – [Additional Options and Functions] 128.61.124.70
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 In addition, a multimeter can be used for continuity and diode testing. In addition, a multimeter can be used for continuity and diode testing.
  
-====Basic Operation====+=====Basic Operation===== 
 +{{ :benchtop:dmm:dmm_front.png?400}}
 The front panel of a multimeter is shown. The screen displays the value of the measurement, and options associated with the measurement can be adjusted with the buttons below the screen. The buttons to the right of the screen are used to adjust the measurement type. The functions in blue above these buttons can be accessed by clicking the **[Shift]** button. On the right side of the DMM is where you connect probes. The front panel of a multimeter is shown. The screen displays the value of the measurement, and options associated with the measurement can be adjusted with the buttons below the screen. The buttons to the right of the screen are used to adjust the measurement type. The functions in blue above these buttons can be accessed by clicking the **[Shift]** button. On the right side of the DMM is where you connect probes.
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 ===Connecting Probes to the Multimeter=== ===Connecting Probes to the Multimeter===
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 For current, the probes must be connected differently, as shown below. The 3A next to the lower input signifies that the multimeter can handle up to 3A of current. If you are trying to measure a current above or close to 3A, another device must be used to obtain an accurate measurement and avoid damaging the multimeter. Current measurements must be taken in series, meaning the path of current must flow through the multimeter. You need to break open a part of the circuit and insert the multimeter in the path.  For current, the probes must be connected differently, as shown below. The 3A next to the lower input signifies that the multimeter can handle up to 3A of current. If you are trying to measure a current above or close to 3A, another device must be used to obtain an accurate measurement and avoid damaging the multimeter. Current measurements must be taken in series, meaning the path of current must flow through the multimeter. You need to break open a part of the circuit and insert the multimeter in the path. 
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 ===Selecting the Measurement Type=== ===Selecting the Measurement Type===
 Once the probes are properly connected, you need to select a measurement type by clicking one of the buttons shown below. DCV means DC volts, ACV means AC volts (this is an RMS voltage), and Ω2W signifies resistance. You can select capacitance by clicking **[Shift]** **[Freq]**, which corresponds to the capacitor symbol above the **[Freq]** button. For current measurements, first confirm that the probes are connected to the current inputs and that the probes are connect to your circuit in series. Then, click **[Shift] [DCV]** for DC Current and **[Shift] [ACV]** for AC Current. If the multimeter is set to auto trigger and auto range, the measured value will be displayed on the screen.  Once the probes are properly connected, you need to select a measurement type by clicking one of the buttons shown below. DCV means DC volts, ACV means AC volts (this is an RMS voltage), and Ω2W signifies resistance. You can select capacitance by clicking **[Shift]** **[Freq]**, which corresponds to the capacitor symbol above the **[Freq]** button. For current measurements, first confirm that the probes are connected to the current inputs and that the probes are connect to your circuit in series. Then, click **[Shift] [DCV]** for DC Current and **[Shift] [ACV]** for AC Current. If the multimeter is set to auto trigger and auto range, the measured value will be displayed on the screen. 
  
-====Additional Measurement Types====+=====Additional Measurement Types=====
 ===Continuity=== ===Continuity===
 Continuity means that there is a complete path for current to flow between two points. In other words, the resistance between those points is very low. When in continuity test mode, the multimeter will beep when there is continuity between the two probes. This is a useful tool to test switches, fuses, connectors, electrical connections, conductors, and other components. For example, a continuity test can be used to verify that two components were soldered together correctly, and that other nearby components were not accidentally soldered together.  Continuity means that there is a complete path for current to flow between two points. In other words, the resistance between those points is very low. When in continuity test mode, the multimeter will beep when there is continuity between the two probes. This is a useful tool to test switches, fuses, connectors, electrical connections, conductors, and other components. For example, a continuity test can be used to verify that two components were soldered together correctly, and that other nearby components were not accidentally soldered together. 
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 First  turn off the circuit power supply, remove the resistor from the circuit, and examine the resistor’s color code to determine its original resistance value and tolerance. For example a resistor with 4 bands of color brown, black, red, and gold would be a 1000 Ohm resistor with 5% tolerance, therefore its should measure between 950 and 1050 Ohms. Next connect test leads to the Digital Multimeter as shown in Figure 8 above. If measuring a resistor at or above 500 Ohms use the 2-wire resistance configuration and if measuring a resistor below 500 Ohms use the 4-wire resistance configuration for greater accuracy. Press **[Ω2W]** button for 2-wire resistance or **[Ω4W]** for 4-wire resistance on the front panel. Set range of the resistance measurement by selecting Range on the display menu using softkey. Next remove test lead resistance by shorting the test probes (touching each end together) and pressing the front panel **[Null]** button, repeat for each pair of test probes. Attach test leads with alligator clips to each end of the resistor to measure its resistance value. If the measured value is outside the tolerance of the original resistance value then the resistor is damaged and should be replaced. A negative resistance value may be reported due to resistor contact with other circuit components while measuring or reversed test probe leads. If the absolute value of the resistance is between the resistor’s tolerance it may be ignored, else ask an IDC peer instructor for help. First  turn off the circuit power supply, remove the resistor from the circuit, and examine the resistor’s color code to determine its original resistance value and tolerance. For example a resistor with 4 bands of color brown, black, red, and gold would be a 1000 Ohm resistor with 5% tolerance, therefore its should measure between 950 and 1050 Ohms. Next connect test leads to the Digital Multimeter as shown in Figure 8 above. If measuring a resistor at or above 500 Ohms use the 2-wire resistance configuration and if measuring a resistor below 500 Ohms use the 4-wire resistance configuration for greater accuracy. Press **[Ω2W]** button for 2-wire resistance or **[Ω4W]** for 4-wire resistance on the front panel. Set range of the resistance measurement by selecting Range on the display menu using softkey. Next remove test lead resistance by shorting the test probes (touching each end together) and pressing the front panel **[Null]** button, repeat for each pair of test probes. Attach test leads with alligator clips to each end of the resistor to measure its resistance value. If the measured value is outside the tolerance of the original resistance value then the resistor is damaged and should be replaced. A negative resistance value may be reported due to resistor contact with other circuit components while measuring or reversed test probe leads. If the absolute value of the resistance is between the resistor’s tolerance it may be ignored, else ask an IDC peer instructor for help.
    
-====Additional Options and Functions====+=====Additional Options and Functions=====
 ===Triggering=== ===Triggering===
-Triggering is used to acquire measurements with greater accuracy. The Digital Multimeter does this by waiting until the test leads read a steady stream of values to report a measurement on the display. The default trigger setting for the Keysight Digital Multimeter is Auto Trigger which takes continuous measurements. Continuous measuring is noisy and is not useful when trying to reach a precise value for a measurement. Continuous measuring is appropriate for checking components for defects and when only estimations of measurement values are needed. In Auto Trigger mode you can stop and resume the taking of measurements by pressing the front panel [Run/Stop] button.+Triggering is used to acquire measurements with greater accuracy. The Digital Multimeter does this by waiting until the test leads read a steady stream of values to report a measurement on the display. The default trigger setting for the Keysight Digital Multimeter is Auto Trigger which takes continuous measurements. Continuous measuring is noisy and is not useful when trying to reach a precise value for a measurement. Continuous measuring is appropriate for checking components for defects and when only estimations of measurement values are needed. In Auto Trigger mode you can stop and resume the taking of measurements by pressing the front panel **[Run/Stop]** button.
  
 ==Set Mode== ==Set Mode==
-Press front panel [Acquire] button and select Trg Src option on the display by using the soft key. Select Auto using the soft key to enter Auto Trigger mode and take measurements continuously. Select Single using the soft key to enter Single Trigger mode and the Digital Multimeter will take a single measurement each time the front panel [Single] button is pressed.+Press front panel **[Acquire]** button and select Trg Src option on the display by using the soft key. Select Auto using the soft key to enter Auto Trigger mode and take measurements continuously. Select Single using the soft key to enter Single Trigger mode and the Digital Multimeter will take a single measurement each time the front panel **[Single]** button is pressed.
  
 ==Auto and Manual Trigger Delay== ==Auto and Manual Trigger Delay==
-The instrument inserts a trigger delay between the occurrence of a trigger and the first measurement. When Delay Auto is selected the instrument automatically determines the delay based on function, range and integration time. However, when Delay Man is selected the user can manually set a delay longer than the automatic delay to allow the input to settle before taking a measurement. These options can be set by pressing the front panel [Acquire] button and using the Delay softkey to select either Delay Auto or Delay Man.+The instrument inserts a trigger delay between the occurrence of a trigger and the first measurement. When Delay Auto is selected the instrument automatically determines the delay based on function, range and integration time. However, when Delay Man is selected the user can manually set a delay longer than the automatic delay to allow the input to settle before taking a measurement. These options can be set by pressing the front panel **[Acquire]** button and using the Delay softkey to select either Delay Auto or Delay Man.
  
 ==Number of Samples== ==Number of Samples==
-In Single Mode the user can specify the number of samples to be taken per trigger by using the Samples/Trigger softkey. Press [Acquire] button and select Samples / Trigger soft key. Press up/down selection buttons on the front panel to set the number of samples. This is useful when trying to take a specific number of samples per measurement to be saved to a CSV file using the USB port on the front panel, for more information see the Save Readings section under Advanced Functionality.+In Single Mode the user can specify the number of samples to be taken per trigger by using the Samples/Trigger softkey. Press **[Acquire]** button and select Samples / Trigger soft key. Press up/down selection buttons on the front panel to set the number of samples. This is useful when trying to take a specific number of samples per measurement to be saved to a CSV file using the USB port on the front panel, for more information see the Save Readings section under Advanced Functionality.
  
 ===Range=== ===Range===
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