The Fluke 45 is a highly versatile, feature-rich 5-digit benchtop dual-display digital multimeter capable of 100,000 counts. Designed for manufacturing test, depot, field service, and R&D applications, it features a multifunction vacuum fluorescent display that allows users to simultaneously view two different parameters of the same signal from a single connection. The instrument supports 16 measurement capabilities, true RMS AC and AC+DC readings, and includes RS-232 as standard with optional IEEE-488.2 connectivity.

Specifications

General

ParameterValue
InterfacesRS-232 (standard), IEEE-488.2 (optional)
DisplayMultifunction vacuum fluorescent dual display, 5-digit, 100,000 counts

Physical

ParameterValue
Power Supply90 to 264 VAC, 50/60 Hz; optional internal rechargeable battery
Operating Temperature0 to 50
Dimensions (W×H×D)216 × 93 × 286
Weight2.4

General Specifications

ParameterValue
Display TypeVacuum Fluorescent Display (VFD), Dual Display
Display Resolution (Digits)5 digits (100,000 counts)
Measurement Speed/Reading Rate2.5, 5, or 20 readings/s
True RMS Measurement TypeAC, AC+DC
Calibration Interval1 Year

DC Voltage Specifications

ParameterValue
DCV Ranges300 mV, 3 V, 30 V, 300 V, 1000 V
DCV Maximum Resolution1 µV
DCV Basic Accuracy (1 Year)±(0.025% of reading + 2 digits) (Slow rate)
DCV Input Impedance10 MΩ
DCV Maximum Input Voltage1000 V DC
Common Mode Rejection Ratio (CMRR)> 120 dB at DC
Normal Mode Rejection Ratio (NMRR)> 60 dB at 50/60 Hz

AC Voltage Specifications

ParameterValue
ACV Ranges300 mV, 3 V, 30 V, 300 V, 750 V
ACV Maximum Resolution1 µV
ACV Bandwidth / Frequency Range20 Hz to 100 kHz
ACV Basic Accuracy (1 Year)±(0.2% of reading + 10 digits) (45 Hz to 20 kHz, Slow rate)
ACV Input Impedance1 MΩ in parallel with < 100 pF
ACV Maximum Input Voltage750 V rms, 1000 V peak
ACV Common Mode Rejection Ratio (CMRR)> 90 dB at DC to 60 Hz

DC Current Specifications

ParameterValue
DCI Ranges30 mA, 100 mA, 10 A
DCI Maximum Resolution0.1 µA
DCI Basic Accuracy (1 Year)±(0.05% of reading + 2 digits) (30 mA to 100 mA ranges)
DCI Maximum Input Current10 A

AC Current Specifications

ParameterValue
ACI Maximum Resolution0.1 µA
ACI Bandwidth / Frequency Range20 Hz to 20 kHz
ACI Maximum Input Current10 A

Resistance Specifications

ParameterValue
Resistance Ranges300 Ω, 3 kΩ, 30 kΩ, 300 kΩ, 3 MΩ, 30 MΩ, 100 MΩ
Resistance Maximum Resolution1 mΩ
Resistance Basic Accuracy (1 Year)±(0.05% of reading + 2 digits) (300 Ω to 300 kΩ ranges)
Measurement Method (2-Wire / 4-Wire)2-Wire

Frequency and Period Specifications

ParameterValue
Frequency Range5 Hz to 1 MHz
Frequency Resolution0.01 Hz
Frequency Accuracy±(0.05% of reading + 1 digit)

Diode and Continuity Testing

ParameterValue
Audible Alarm IndicatorYes

Math and Advanced Functions

ParameterValue
Statistical Functions (MIN/MAX/AVG)MIN/MAX mode
Null / Relative ModeYes (RELATIVE)
Limit Testing / CompareCompare (Hi/Lo/Pass)
dB / dBm FunctionYes
dBm Reference Impedances2 Ω to 8000 Ω (21 selectable reference impedances)

Connectivity and Control Interfaces

ParameterValue
Standard Data InterfacesRS-232
Baud Rate Settings300 to 9600 baud

Environmental and Safety Specifications

ParameterValue
Storage Temperature Range-40 °C to +70 °C

Power Requirements

ParameterValue
AC Line Voltage90 V to 264 V AC
Maximum Power Consumption15 VA
Battery Operation OptionOptional internal rechargeable lead-acid battery
Battery Life (Typical)8 hours

Physical Characteristics

ParameterValue
Rack Mount CompatibilityOptional rack-mount kit available

Inputs & Protection

ParameterValue
Maximum Common Mode Voltage1000V dc or peak ac (COM to Earth ground)

AC Performance

ParameterValue
AC Crest Factor3.0 at full scale

Diode Test

ParameterValue
Diode Test Range3.2 V

Environmental

ParameterValue
Temperature Coefficient0.1 × (specified accuracy) / °C (< 18 °C or > 28 °C)
Operating Relative HumidityUp to 90% (0 °C to 28 °C); Up to 80% (28 °C to 40 °C); Up to 70% (40 °C to 50 °C)

Compliance & Certifications

ParameterValue
Safety ComplianceUL 1244, IEC 348, CSA C22.2 No. 231
Electromagnetic Interference (EMI)FCC Part 15 Class B, VDE 0871 Class B

Performance

ParameterValue
Warm-Up Time30 minutes to rated accuracy

Measurement Features

ParameterValue
Touch HoldYes (captures and holds stable readings)

Power

ParameterValue
Optional Battery Type8V Sealed Lead-Acid

Technology

Digital Multimeter (DMM)

Applications

Benchtop test, manufacturing test, depot and field service, R&D