1-203-402-0477 [email protected]


GrayWolf Sensing Solutions introduces an extremely accurate differential air pressure (∆P) micromanometer with exceptional low-end resolution. By combining auto-ranging and auto-zeroing with the latest sensor technology, this handheld digital meter offers superb sensitivity, yet a broad measurement range. Building on decades of experience with earlier Zephyr models, this 4th generation Zephyr achieves the best accuracy, widest range, and runs on GrayWolf’s advanced new WolfOS™ operating system with an easy-to-use Graphical User interface (GUI) and enhanced user features.

There is a trade-off between range and low-end resolution with commercially available ∆P sensors. For many Indoor Air Quality (IAQ), Heating Ventilation Air Conditioning (HVAC), Industrial Hygiene (IH) or other applications, extremely low-end ∆P resolution is critical, yet a wide measurement range is highly desirable.   GrayWolf solves this by incorporating a 250.0 Pa (1.000“H2O) range sensor and a 10KPa (40.0“H2O) sensor on the same board, seamlessly auto-ranging from one sensor to the other dependent on the detected pressures. A further issue for low-end measurements, such as determining pollutant pathways, is that sensor drift at these minute pressures may be significant over a matter of only minutes. Most low-range digital manometers rely on manual zeroing ahead of each reading. But for long-term monitoring, a meter must re-zero automatically for the readings to be reliable over time. The Zephyr XM does exactly this, auto-zeroing both sensors every 2 minutes (user-adjustable to longer zeroing intervals).

This combination of unequaled low-end sensitivity, and wide-range measurement capability, makes the Zephyr XM ideal for applications including:

  • Testing filter performance, the most reliable way to rate dirt loading on the filter or potential duct leakage (especially important as filters with higher MERV ratings are installed in response to COVID-19).
  • Investigating pollutant pathways to confirm gases, toxins, viruses, etc. are not transported in unanticipated ways between spaces.
  • Verifying positive pressure in occupied areas during local area construction.
  • Monitoring/logging positive pressure vs. negative pressure over time for adjacent zones such as classroom/kitchen, childcare area/parking garage, general office/laboratory.
  • Determining pressure drop across coils, diffusers, registers, fans, orifice plates.
  • Measuring static pressure, air velocity (up to 100m/s, 19,500fpm) and volumetric airflow with a pitot static tube.
  • Alternatively connect a telescoping, articulating hotwire anemometer for exceptionally accurate (+/-2% of reading from .05 to 30m/s, 10 to 6000fpm), low-range airflow measurements.
  • Measuring temperature and %RH with an optional plug-in probe (direct connect or with handle and 1m cable)

The Zephyr XM displays and data-logs readings, logging over time at user-selectable intervals or as instantaneous “snapshot” logs. The meter also provides powerful annotation capabilities. Notes are easily attached to data files on-site for efficient, reliable documentation. Add text notes via the virtual keyboard.  Attach extensive audio notes with the built-in voice recorder.   Reports are proficiently generated from information in the field. The included WolfSense® PC software enables simple download, analysis, graphing and simple report generation. Optional “Advanced Report Generator” software automates the entire reporting process.

An industry leading manufacturer of air monitoring instrumentation, established in 1998, GrayWolf has manufactured high quality differential pressure meters since 2005 after acquiring the Solomat Zephyr ∆P range at that time. GrayWolf continues to service Solomat branded units (subject to parts availability), and older GrayWolf-badged Zephyrs. GrayWolf’s environmental instrumentation is employed by industry professionals in manufacturing plants, high rise buildings, hospitals, airports, schools, universities, refineries and many other types of facilities. Worldwide management, sales and customer support is headquartered in Shelton, CT (USA). The primary manufacturing facility is in Ireland, with support available through a global network of distributors.

For more information please contact:

Cassandra Rivera
Marketing Administrator

GrayWolf Sensing Solutions
6 Research Drive 
Shelton, CT 06484 USA
1-203-402-0477 tel.
[email protected]

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