Fluke 187 user manual Making Measurements, Measuring Voltage

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Introduction

Chapter 3 explains how to make measurements. Most measurement functions can be selected by using the rotary switch.

White letters or symbols identify primary functions; blue letters or symbols identify alternative functions. Press the blue button to access these alternate functions.

Frequency-related functions can be selected (Hz, duty cycle, and pulse width) when the rotary switch is in any volts or amps position.

Measuring Voltage

Voltage is the difference in electrical potential between two points. The polarity of ac (alternating current) voltage varies over time, while the polarity of dc (direct current) voltage is constant over time.

Chapter 3

Making Measurements

Ranges available in volts functions are:

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5.0000 V, 50.000 V, 500.00 V, 1000.0 V

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50.000 mV, 500.00 mV, and 5000.0 mV

Readings in the 5000.0 mV range overload (0L) near 3000 mV ac or dc. The 5000.0 mV range overlaps the 5.0000 V range to provide direct reading display for Fluke accessories that have a millivolt output with limits scaled by 1000. For example, the Fluke 80i-1000 Current Clamp provides 1 mV ac per amp measured up to 1000 amps.

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Contents Model 187 Lifetime Limited Warranty Table of Contents Model 187 Making MeasurementsIii Maintenance SpecificationsList of Tables List of Figures Viii Safety Information Before You StartContacting Fluke Safety Information WWarningBefore You Start Symbols International Electrical SymbolsGetting Acquainted IntroductionTurning the Meter On Battery Considerations Automatic Power OffLow Battery Indication Automatic Backlight OffRotary Switch Rotary SwitchPushbuttons PushbuttonsRotary Switch Selections Position Rotary Switch Function Blue Key FunctionRotary Switch Positions View MEMButton Pushbuttons Yellow Button Description Function Pushbuttons Button Description Yellow Button FunctionSelecting the Range Understanding the DisplayPrimary Display Bar Graph Secondary DisplayDisplay Features Number Feature Display Features Description Display Features Number 8.8.8Number Feature Display Features DescriptionDisplay Features Number 51000 FMS8888 HM8888 8.8Using the Input Terminals Input TerminalsUsing Display Hold Display Hold and AutoHOLDUsing AutoHOLD Using MIN MAXModel 187 Using Fast MN MX Min Max AvgUsing Relative Mode REL Using Hold with MIN MAX or Fast MN MXMaking Measurements Measuring VoltageMeasuring AC Voltage AC Voltage MeasurementDB Measurements in AC Volts Functions DBm DisplayMeasuring DC Voltage Both AC and DC Voltage MeasurementsAC over DC DC over AC AC and DC DisplayMeasuring Resistance Capacitors before measuring resistanceOFF Testing for Continuity Automatically subtract this valueUsing Conductance for High Resistance Tests For in-circuit tests, turn circuit power off Conductance Measurement Measuring Capacitance Testing Diodes Capacitance MeasurementDiode Test Measuring Temperature Shock, do not connect the thermocouples toElectrically live circuits Measuring Current Input RangesInput Alert Feature Measuring CurrentMeasuring AC Current Following are some tips for measuring current11. AC Current Measurement Measuring DC Current Total current to circuit Current through one componentMeasuring Frequency 13. Functions Allowing Frequency MeasurementMeasuring Duty Cycle 14. Hz DisplayMeasures Positive Pulse Measures Negative PulseMeasuring Pulse Width 16. Duty Cycle DisplayStart and Stop on Positive Slope Start and Stop on Negative Slope18. Pulse Width Display Using Memory & Communications Features Types of MemorySaved Readings Memory Logged Readings MemoryStoring Saved Readings Starting LoggingStopping Logging Viewing Memory Data To avoid electric shock, disconnect the testView Display MEMUsing Communications 187 Clearing MemoryChanging the Default Settings Selecting Setup OptionsFunction Specific Setup Selections Factory DefaultPrecondition OptionCommon Setup Selections ChoicesAdjusting the Temperature Offset Changing the Default Settings Selecting Display Resolution 3 1/2 or 4 1/2 Digits Setting the Power Off TimeoutSetting the 24-Hour Clock Setting the Line Main FrequencyReturning to Factory Defaults Saving Setup OptionsMaintenance Introduction General MaintenanceTesting the Fuses Replace F2 if Replace F1 if Displayed Replacing the Batteries Battery and Fuse Replacement Replacing the Fuses User-Replaceable PartsCase of Difficulty MP8 MP9 Specifications Safety and CompliancesPhysical Specifications Feature Summary Basic Specifications Detailed Accuracy Specifications Accuracy Function 45-1 kHz20 kHz KHz-100 kHzDC a 500.00 Ω Capacitance Diode Test MIN MAX AVG Frequency Counter Sensitivity Burden Voltage A, mA, µAInput Characteristics