Technical Foundation
What Is a Light Meter?
A light meter measures illuminance — the amount of light falling on a surface — using a photodiode sensor whose response is filtered to match human eye sensitivity for standard lux and foot-candle readings. Lux and foot-candle are the same underlying measurement in different units (1 foot-candle ≈ 10.76 lux), and most workplace lighting codes and standards specify a minimum illuminance level in one or the other depending on region and industry.
UV light meters use a different sensor entirely, filtered to a specific UV wavelength band (UVA, UVB or UVC) rather than the visible spectrum, and are used for applications like UV curing process control or UV disinfection verification rather than general lighting. PAR meters measure photosynthetically active radiation specifically for horticultural lighting, a still different measurement (µmol/m²/s of photons in the 400-700nm range usable by plants) that a standard lux meter cannot substitute for.
Prefer a quick quote?
Get Light Meters Pricing in Your Inbox
Skip the search — tell us the measurement unit (lux/fc/UV/PAR) and range you need and we will come back with pricing.
| Spec | What It Means | Why It Matters |
|---|---|---|
| Measurement Type | Lux, foot-candle, UV index/irradiance, PAR | Each measures a different property — not interchangeable across applications |
| Measurement Range | Low-light to high-intensity, per meter spec | Must cover both the dimmest and brightest conditions being measured |
| Sensor Spectral Response | Photopic (visible) vs. UV-filtered vs. PAR-filtered | Determines what wavelength band the meter is actually sensitive to |
| Accuracy & Calibration | Percent of reading accuracy, NIST-traceable cal cert | Required for code-compliance documentation and regulated process control |
| Data Logging | Single reading vs. logging/averaging over time | Logging supports documented compliance surveys and trend monitoring |
Shop Light Meters
Browse Light Meters Sub-Categories
Organised by measurement type. Pick a sub-category, or describe the lighting environment you're measuring and let ChatMRO match the meter.
How it works
From Half-Remembered Part Number to PO, in Three Steps.
Ask
Type an MPN, paste a spec sheet, or describe the part in plain English. ChatMRO understands engineer-speak.
Compare
Side-by-side specs, cross-references, and equivalents from multiple sources — without the clutter of endless browser tabs.
Quote & Buy
Request a quote or add to cart. Volume discounts, VAT-aware pricing, and consolidated procurement — all in one place.
Applications
Where Light Meters Get Used
Light meters are specified anywhere illuminance, UV intensity or PAR needs to be measured and documented against a standard.
Workplace Safety & Lighting Compliance
Verifying illuminance levels in industrial and commercial workplaces meet OSHA and building code minimums.
Retail & Commercial Lighting Design
Measuring foot-candle levels across retail floors to verify lighting design meets merchandising and energy targets.
Horticultural & Controlled Environment Agriculture
PAR meters measuring usable light intensity for indoor grow operations and greenhouse supplemental lighting.
UV Curing & Disinfection Process Control
UV light meters verifying dose and intensity for UV curing lines and UV disinfection systems.
Photography & Film Production
Incident and reflected light meters used for exposure setting in professional photography and cinematography.
FAQ
Light Meters Questions, Answered
What's the difference between lux and foot-candles?
Both measure illuminance — the amount of visible light falling on a surface — but in different unit systems: lux is the metric unit (lumens per square meter) and foot-candles is the imperial unit (lumens per square foot). One foot-candle equals approximately 10.76 lux, and most meters can switch between the two units, but check which unit your applicable code or standard specifies before taking compliance readings.
Can a standard lux meter measure UV light?
No — standard lux and foot-candle meters use a photopic sensor filtered to match human visible-light perception and deliberately excludes UV wavelengths. Measuring UV intensity requires a dedicated UV meter with a sensor filtered to the specific UV band (UVA, UVB or UVC) relevant to your application, such as UV curing or germicidal UV disinfection.
Why can't I use a lux meter for horticultural grow light measurement?
Lux meters weight their reading toward the green-yellow wavelengths human eyes are most sensitive to, but plants use a different, broader range of the light spectrum (400-700nm) for photosynthesis, weighted differently than human vision. A PAR meter measures photosynthetically active radiation specifically in units plants actually use (µmol/m²/s), giving a meaningful reading for grow light intensity that a lux meter cannot provide.
How often should a light meter be calibrated?
For general workplace or retail lighting checks, annual calibration is a common baseline, but applications requiring documented regulatory compliance (safety audits, UV process validation) often call for more frequent calibration per your quality system's requirements. Always use a NIST-traceable calibration certificate when readings need to support compliance documentation.
What accuracy do I need for OSHA workplace lighting compliance checks?
OSHA references specific minimum illuminance levels for different work areas and tasks, and while OSHA doesn't mandate a specific meter accuracy class, using a meter with a stated accuracy of around ±5% of reading and current calibration gives defensible, credible readings if compliance is ever questioned. Confirm any industry-specific standard your facility follows for more precise accuracy requirements.
Keep browsing
Related Categories
Explore More
Find Your Next Part Now.
Describe a part number, spec or what it does.