UT505A Basic Insulation Resistance DMM

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UNI-T UT505A Handheld Insulation Resistance Tester

The UNI-T UT505A Handheld Insulation Resistance Tester emerges as a critical tool for electrical professionals who demand precision, reliability, and comprehensive diagnostic capabilities. Bridging the gap between traditional multimeters and advanced testing instruments, the UT505A delivers unparalleled insights into electrical system integrity across multiple industries and applications.

Technical Specifications

Parameter	Specification
Insulation Resistance Range	50V: 0.1MΩ~50MΩ (±3%+5), 50MΩ~1GΩ (±3%+3) 100V: 0.1MΩ~100MΩ (±3%+5), 100MΩ~1GΩ (±3%+3) 250V: 0.1MΩ~200MΩ (±1.5%+5), 200MΩ~1GΩ (±1.5%+5) 500V: 0.1MΩ~500MΩ (±1.5%+5), 500MΩ~1GΩ (±1.5%+5) 1000V: 0.1MΩ~2000MΩ (±1.5%+5), 2GΩ~9.9GΩ (±10%+3)
Voltage Range	3.0V to 700V
Current Range	0.5mA to 24A
Power Range	1W to 12kW
Display	6000-count LCD
Power Source	6 × 1.5V batteries (LR6)
Dimensions	103mm × 225mm × 59mm
Weight	630g

UT505 Series Comparison

Feature	UT505A	UT505B
Insulation Resistance Accuracy	0%~10% variation	0%~20% variation
Auto Fuse Check	No	Yes
High Voltage Output Alarm	No	Yes
Data Storage	Standard	99-group data storage
Recommended Applications	Standard electrical testing and maintenance	Advanced diagnostics and critical infrastructure testing

Key Features

True RMS measurement technology
Insulation resistance testing from 50V to 1000V
Versatile measurement ranges (0.01MΩ to 100GΩ)
Analog bar graph display for intuitive reading
DAR and PI tests with comprehensive timing measurements
Comparison measurement functionality
Auto power-off and range selection
LCD backlight for low-light environments
Data hold feature
Low battery indication
6000-count display resolution
Comprehensive compliance with IEC 61557 standards

Professional Applications

Industrial Maintenance and Reliability

Manufacturing facilities rely on the UT505A to prevent unexpected equipment failures and optimize maintenance schedules. By providing detailed insights into motor insulation, electrical panel conditions, and critical machinery electrical systems, the instrument helps maintenance engineers:

Identify potential insulation breakdown before catastrophic failures occur
Establish baseline measurements for long-term equipment health tracking
Validate electrical system integrity during preventive maintenance routines

Electrical Infrastructure Management

Power distribution professionals utilize the UT505A for comprehensive assessment of:

Transformer insulation integrity
Underground and overhead cable condition
Switchgear and distribution equipment diagnostics
Critical infrastructure reliability verification

Renewable Energy Systems

Solar and wind energy technicians depend on precise insulation testing to ensure:

Solar panel array electrical integrity
Wind turbine generator insulation performance
Power conversion equipment reliability
Long-term system efficiency verification

Telecommunications and Data Center Infrastructure

Critical communication infrastructure requires meticulous electrical testing. The UT505A supports:

Telecommunications equipment insulation assessment
Data center power system diagnostics
Network infrastructure reliability verification
Preventive maintenance of mission-critical electrical systems

Diagnostic Test Methods: DAR and PI

Dielectric Absorption Ratio (DAR) Test

The Dielectric Absorption Ratio (DAR) is a critical diagnostic method for assessing insulation condition. It involves measuring the ratio of insulation resistance at two specific time intervals, typically 30 seconds and 60 seconds after applying a test voltage.

Key Applications:

Detecting moisture contamination in insulation
Identifying early signs of insulation degradation
Evaluating the polarization characteristics of insulating materials
Quick assessment of insulation health in motors, cables, and electrical equipment

A DAR value significantly different from 1 can indicate:

Moisture presence
Contamination
Insulation breakdown
Potential equipment reliability issues

Polarization Index (PI) Test

The Polarization Index (PI) provides a more comprehensive evaluation of insulation condition by measuring the ratio of insulation resistance at 10 minutes to the resistance at 1 minute after applying a test voltage.

Critical Applications:

Long-term insulation health assessment
Detecting gradual insulation deterioration
Identifying complex insulation defects
Comprehensive evaluation of electrical system reliability

PI Test Interpretation:

PI > 2: Generally indicates good insulation condition
PI 1-2: Suggests potential insulation issues
PI < 1: Indicates significant insulation degradation

These advanced diagnostic tests transform the UT505A from a simple resistance meter to a powerful predictive maintenance tool.

Customer Testimonials

"The UT505A has become an indispensable tool in our electrical maintenance arsenal. Its precision and versatility have helped us catch potential issues before they become critical failures."
- Elena R., Industrial Maintenance Engineer

"As a renewable energy technician, I rely on the UT505A's detailed diagnostic capabilities to ensure our solar installations maintain peak performance and reliability."
- Michael K., Solar Systems Specialist

Warranty and Support

UNI-T provides a comprehensive 1-year warranty on the UT505A, covering manufacturing defects and component failures under normal use conditions. Our dedicated technical support team offers expert guidance to help you maximize the value of your investment and ensure reliable electrical testing capabilities.

Feature	Specification
Model Number	UT505A
TRMS	true
Max IR V	1,000VDC
Max IR Resistance Ω	20GΩ
Low IR Resistance Ω	20kΩ
Count	6,000
Warranty	1 year
Shipping Dimmensions (L x W x H)	x x
Shipping Weight