The Sonel MM-640 is a professional low resistance meter designed for UK industrial electricians, commissioning engineers and maintenance technicians who need reliable milliohm measurements on high-capacity electrical systems. It provides accurate results for bonding checks, busbar testing, transformer winding assessment and protective conductor verification.
With selectable test currents up to 10 A, the MM-640 ensures stable, repeatable readings when inspecting installations where low-resistance integrity is critical.
What makes the MM-640 different from other low resistance testers?
Its standout feature is the high test current capability (up to 10 A) combined with compact, field-ready portability. Many low resistance meters offer lower current output, leading to unstable readings on heavy-duty installations. The MM-640 delivers strong, dependable test current even in challenging environments, making it ideal for industrial and utility work.
How does the MM-640 support everyday electrical testing?
From checking earth bonding on large switchgear to validating cable joints and protective conductors, the MM-640 speeds up routine testing with its clear display, simple controls and fast measurement response. It is built for technicians who require accuracy and efficiency on every job.
Order today to enjoy free delivery, expert support and our 90-day satisfaction guarantee. Need advice? Our team is here to assist you.
Why choose Instrotech for your electrical test equipment?
With over 40 years’ experience supporting UK electricians, technicians and engineers, Instrotech is your trusted partner for quality tools and expert service. When you purchase from us, you benefit from:
Free UK shipping on all orders
Access to our knowledgeable technical support team
Available calibration services to maintain safety compliance
A 90-day money-back guarantee for complete peace of mind
We’re committed to helping you work safely and efficiently with industry-leading products and ongoing support.
