
Measure illumination up to 99,999 lux with professional-grade accuracy. The ultimate workplace and photography light meter.
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Avg Rating (221+ reviews)
Satisfaction Rate
Loved Across Britain

£392.19 inc. VAT (£326.82 ex. VAT)
A professional-grade, pocket-sized digital lux light meter designed for accurate workplace and photography illumination measurement up to 99,999 lux.
Next-day delivery from our UK warehouse
Full manufacturer warranty with local support
Measures extreme brightness with precise accuracy
Sensor spectral sensitivity matched to the human eye



As a facilities manager, I need a reliable workplace light meter for our annual HSE audits. The Testo 540 is brilliant-the human eye calibration means I can trust the readings completely, unlike the cheap generic meters we used to buy.
I use this for checking continuous lighting setups in my video studio. The 99,999 lux range is incredible, and the digital display is so easy to read. Next day delivery from BestSquare was a lifesaver for my shoot.
An outstanding piece of lighting measurement equipment. The build quality is exactly what you expect from Testo. The hold function is particularly useful when reaching over desks to check working plane illumination.
Great digital lux meter. Highly accurate and the protective cap is a nice touch. I just wish it came with a soft carrying pouch as well as the hard cap, but overall it's a solid 4.5/5 for site work.
I upgraded from a free phone app to this professional lux light meter and the difference is night and day. The readings are actually stable and repeatable. Worth every penny for our commercial lighting installations.
Very accurate for HVAC and electrical commissioning. The screen is clear and the max/min function saves me a lot of time when surveying a large open-plan office.

At BestSquare, we understand that accurate lighting measurement is critical for both workplace safety and creative perfection. Founded in the UK, we specialise in providing professionals with dependable, high-precision illumination meters that out-perform generic smartphone apps and low-cost alternatives.
Our flagship Testo digital lux meter is trusted by health and safety managers, facilities teams, and studio photographers across Britain. We know that complying with HSE and CIBSE lighting guidelines requires equipment you can rely on, which is why we only stock professional-grade instruments with proven repeatability and robust build quality.
Backed by dedicated UK customer support, fast dispatch from our local warehouse, and a comprehensive 2-year warranty, BestSquare is your definitive source for professional light measurement. Whether you are auditing office ergonomics or setting up continuous studio lighting, we provide the tools to measure with absolute confidence.
Our products are designed and supported in the UK, ensuring superior quality and fast tracked delivery from our British warehouse. We offer free UK delivery on all orders, eco-friendly packaging to reduce carbon footprint, and warm, direct customer service. Every order is backed by a generous 30-day returns policy under the UK Consumer Rights Act 2015 — you are always protected.

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