UNI-T UT501A Insulation Resistance Tester Megohmmeter

Comprehensive Insulation Resistance Diagnostic System

The UNI-T UT501A is a high-precision, portable digital insulation resistance tester engineered specifically for evaluating the dielectric integrity of electrical equipment, power generation machinery, transformers, electric motors, and complex industrial wiring systems. Built upon a modern micro-processing core paired with dual-slope Analog-to-Digital conversion, the UT501A delivers stable, high-accuracy measurements across diverse field conditions. Designed to meet demanding testing standard operating procedures, this instrument effectively detects insulation breakdown, aging, moisture ingress, and thermal degradation before critical equipment failures occur.

Multi-Voltage Output and Resistance Measurement Capabilities

Equipped with selectable direct current output test voltages of 100V, 250V, 500V, and 1000V, the UT501A accommodates low-voltage control circuits as well as heavy industrial power systems. The meter provides an expansive insulation resistance measurement range spanning from 0.00M ohm up to 5.00G ohm with automatic range selection. It features precise threshold detection: 100V output (0.00M ohm to 100M ohm), 250V output (0.00M ohm to 99.9M ohm, 100M ohm to 5.00G ohm), 500V output (0.00M ohm to 99.9M ohm, 100M ohm to 5.00G ohm), and 1000V output (0.00M ohm to 99.9M ohm, 100M ohm to 5.00G ohm). Additionally, the device incorporates an integrated AC voltage meter capable of measuring line-to-line or line-to-ground potential from 30V to 750V across 50Hz and 60Hz power frequencies.

Specifications of UT500 Series Insulation Resistance Testers

Specifications	Range		UT501A	UT501B	UT502A
Insulation resistance (Ω)	Test voltages	100V/250V/500V/1000V	0%~10%
		250V/500V/1000V		0%~10%
		500V/1000V/2500V			0%~10%
	100V	0MΩ~100MΩ	±(3%+5)
	250V	0MΩ~99.9MΩ	±(3%+5)	±(3%+5)
		100MΩ~5GΩ	±(5%+5)	±(5%+5)
	500V	0MΩ~99.9MΩ	±(3%+5)	±(3%+5)	±(3%+5)
		100MΩ~5GΩ	±(5%+5)	±(5%+5)	±(5%+5)
	1000V	0MΩ~99.9MΩ	±(3%+5)	±(3%+5)	±(3%+5)
		100MΩ~5GΩ	±(5%+5)	±(5%+5)	±(5%+5)
	2500V	0MΩ~99.9MΩ			±(3%+5)
		100MΩ~9.9GΩ			±(5%+5)
		10GΩ~20GΩ			±(10%+5)
	Load current	50V (R=50kΩ) 1mA	0%~10%	0%~10%	0%~10%
		100V (R=100kΩ) 1mA	0%~10%	0%~10%	0%~10%
		250V (R=250kΩ) 1mA	0%~10%	0%~10%	0%~10%
		500V (R=500kΩ) 1mA	0%~10%	0%~10%	0%~10%
		1000V (R=1MΩ) 1mA	0%~10%	0%~10%	0%~10%
		2500V (R=1MΩ) 1mA			0%~10%
Short-circuit current			<2mA	<2mA	<2mA
Low resistance (Ω)	0.01Ω~200Ω (about 5.0V/>200mA）			±(2%+3)	±(2%+3)
AC voltage (V)	30V~750V		±(2%+3)
	30V~600V			±(2%+3)	±(2%+3)
Features
Display count			2000	2000	2000
DAR	60s/15s and 60s/30s			✔	✔
PI				✔	✔
Auto range/Low battery indication			✔	✔	✔
LCD backlight/Light alarm			✔	✔	✔
Buzzer alarm/High voltage indication			✔	✔	✔
Overload indication/Auto discharge			✔	✔	✔ Tags: UNI-T , Insulation Tester , Megohmmeter , UT501A , High Voltage Tester , Testing Equipment , Measurement Tools Ginō AI Ginō AI - Nerokas AI Assistant ✕ Jambo! I am Ginō, a Nerokas AI Assistant and Africa's best Open Hardware Facilitator AI agent here to help. In order to serve you better and to help me give you accurate shipping estimates as we begin, could you please tell me your name and your location/city? You can also ask about any hardware or type I'd like to order, I am looking for..., you can also LIST all SKUs & Quantity of desired items from our website here for me to help you Checkout automatically at anytime to fast-track your requests and orders. ↑