From air quality to acoustics, these must-have tools help facilities managers maintain safe, efficient, and compliant buildings.
Managing a facility—whether it’s an office block, warehouse, healthcare centre or school—means keeping a constant eye on the environment. Temperature, air quality, sound, and lighting all play a role in comfort, safety, compliance, and energy efficiency.
Environmental testers are essential tools in a facilities manager’s toolkit. They provide data-driven insights that help you take action before problems arise, reduce energy costs, and meet legal standards. If you’re reviewing your equipment or just starting out, here are the top five environmental testers every facilities team should consider owning.
1. CO₂ and Air Quality Monitors
In recent years, air quality has taken centre stage, especially in schools, offices and healthcare environments. Poor ventilation can increase the spread of airborne illnesses, reduce cognitive performance, and raise carbon dioxide (CO₂) levels beyond safe thresholds.
Why it matters:
High CO₂ levels lead to fatigue, poor concentration, and headaches
Indoor air quality is now a key part of many organisations’ health and wellbeing strategies
Supports compliance with HSE and building ventilation guidelines
Critical for post-COVID building management and maintaining productivity in enclosed spaces
Recommended tool:
Extech CO250 Indoor Air Quality Meter – A portable, professional-grade monitor that measures CO₂, temperature, and humidity. It uses a maintenance-free NDIR (non-dispersive infrared) sensor and offers statistical analysis for TWA and STEL exposure levels. The CO250 can measure CO₂ concentrations up to 5,000 ppm and supports data logging and PC analysis via RS-232 interface.
The device has a wide temperature range (-10 to 60°C), a humidity range of 0 to 99.9%, and includes a backlit LCD display, audible alarm, and optional battery or mains power. It’s ideal for facilities managers who need accurate, portable air quality data to support ventilation audits or indoor comfort checks.
Bonus benefit:
Supplied with Extech software and cables for easy PC connectivity, enabling data downloads and trend analysis—ideal for health & safety reports or indoor air quality compliance.
2. Sound Level Meters
Excessive noise doesn’t just irritate—it can damage hearing and lower productivity. For facilities located near plant machinery, busy roads or production lines, measuring sound is essential for compliance and wellbeing.
Why it matters:
Ensures compliance with the Control of Noise at Work Regulations 2005
Identifies when ear protection zones are required
Helps in designing quieter, more comfortable environments
Helps facilities teams maintain good acoustic quality in meeting rooms, classrooms, and open-plan areas
Recommended tool:
Martindale SP79 Class 2 Sound Level Meter – A reliable, compact and easy-to-use sound level meter designed for accurate noise measurements in industrial and office settings. With A and C frequency weighting and fast/slow time weighting, it provides the flexibility required for different workplace scenarios. The SP79 features a high-contrast 4-digit LCD with bar graph, True-RMS detector, and a wide measurement range from 32 to 130dB.
It complies with BS EN 61672-1:2003, includes AC/DC output for data analysis, and comes supplied with a windscreen, battery, and durable hard case. For added precision, the optional SPC70 Class 2 Calibrator can be used to verify accuracy before and after readings.
Bonus benefit:
Lightweight enough for handheld use but can also be tripod-mounted for long-term monitoring. Ideal for maintaining HSE compliance or logging sound levels across different building zones.
3. Temperature and Humidity Meters
Even with a robust HVAC system, localised temperature and humidity imbalances can creep in—especially in older buildings or large premises. Monitoring these conditions ensures thermal comfort and prevents risks like condensation or mould growth.
Why it matters:
Improves employee comfort and productivity
Prevents damage to sensitive equipment, electronics, and stock
Aids in managing energy consumption and HVAC efficiency
Crucial in storage environments, particularly for pharmaceuticals, electronics, or archived materials
Recommended tool:
Fluke 971 Temperature Humidity Meter – Designed for fast, accurate readings in demanding indoor environments, the Fluke 971 is ideal for HVAC professionals and facilities engineers. Its compact, lightweight build and intuitive interface make it easy to carry and operate across multiple locations. The backlit dual-display shows temperature and humidity simultaneously, ensuring clear visibility—even in low-light conditions.
Equipped with an NTC temperature sensor and an electronic capacitance polymer film humidity sensor, the Fluke 971 delivers reliable real-world performance. It includes built-in memory for storing up to 99 readings, allowing trend tracking and spot-check comparisons without additional tools.
Bonus benefit:
Housed in a rugged protective holster with a belt clip and powered by four AAA batteries (up to 200 hours of runtime), the Fluke 971 is built to last. Whether you’re auditing an office, checking plant equipment, or maintaining a server room, it’s a dependable solution that supports accurate environmental monitoring on the go.
4. Light Meters (Lux Meters)
Lighting quality is often overlooked but is a key part of workplace wellbeing and regulatory compliance. Areas such as stairwells, corridors, warehouses, and workstations require specific lux levels to ensure safe movement and effective working conditions.
Why it matters:
Prevents visual fatigue, discomfort, and health complaints among staff
Ensures legal compliance with workplace lighting regulations
Supports safe navigation in low-light areas such as stairwells or loading bays
Helps optimise energy use by identifying areas with over-illumination
Assists with verifying lighting levels during building renovations or energy audits
Recommended tool:
Extech LT300 Light Meter – A versatile and precise instrument designed for high-accuracy illumination measurement. The LT300 covers a wide range up to 400,000 Lux (or 40,000 foot-candles), with a high resolution of 0.1 Lux/Fc and accuracy within 5%. It features both digital and analogue bar graph displays, a backlit LCD screen, and a Peak mode to capture the highest recorded lux level.
Additional features include a Relative mode to monitor changes in lighting, Min/Max and Data Hold functions, and a cosine- and colour-corrected sensor for reliable results in real-world conditions. Ideal for assessing general lighting, task lighting, or security illumination such as ATM areas and perimeter floodlights.
Bonus benefit:
Supplied with a remote light sensor on a coiled cable, the LT300 allows for hands-free readings in hard-to-reach or fixed locations. It also includes a protective holster and pouch case for portability—making it an excellent choice for facility inspections, energy assessments, or lighting maintenance routines.
5. Multifunction Environmental Testers
For teams needing a versatile, space-saving option, multifunction testers can combine temperature, humidity, light, sound, and more in a single handheld device. Ideal for small teams, general audits, or on-the-spot checks across varied building zones.
Why it matters:
One device for many testing needs
Saves space and budget
Ideal for general site inspections or regular maintenance checks
Perfect for mobile engineers or temporary site surveys where portability is essential
Recommended tool:
Extech EN300 5-in-1 Environmental Meter – A versatile and rugged multifunction tester that measures humidity, temperature, air velocity, light, and sound in one compact instrument. With a built-in vane anemometer and precision humidity sensor, the EN300 provides fast, accurate readings across all five environmental parameters. The large LCD allows for simultaneous display of temperature with either air velocity or humidity, while in light and sound modes, the screen rotates for easy readability.
It includes Min/Max functions, data hold, and tripod compatibility. With features like a precision thin-film humidity sensor, thermistor, and photo diode with cosine and colour correction filters, it offers excellent diagnostic capabilities in industrial, commercial, and HVAC environments.
Bonus benefit:
Ideal for facilities engineers tackling a broad range of site checks, the EN300 meets Class 2 IEC 61672 sound level standards and is tripod-mountable for hands-free monitoring. Optional software enables data logging and reporting, making it a strong choice for both everyday use and compliance documentation.
In Summary: Data Drives Action
Environmental testers aren’t just for ticking boxes—they’re decision-making tools. They help facilities managers spot inefficiencies, protect occupants, and reduce overheads by offering real-time data and historical trends.
Investing in quality testers helps build a proactive maintenance culture and supports wider business goals like sustainability, staff wellbeing, and operational resilience. From air quality to acoustics, facilities managers are increasingly expected to deliver safe, productive spaces—and environmental testers are key to achieving that.
At Test4Less, we stock a wide range of environmental testers from trusted brands like Extech, Testo, Fluke and Martindale available for outright purchase or rental. Whether you’re equipping a single site or managing a nationwide estate, our team can help recommend the right tools to match your requirements.
Need help choosing the right tester for your facility? Get in touch with our technical team for expert, no-pressure advice.