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Handheld, highly accurate, auto-zeroing

Differential Pressure Meters, Micromanometers

Unprecedented differential pressure measurement accuracy (yet a wide range) for critical pollutant pathway monitoring, ventilation assessment, filter performance testing, general HVAC measurement and many other applications. GrayWolf AdvancedSense meters include auto-ranging dual DP sensors, as well as auto-zeroing (to maintain low-end precision). GrayWolf DP instruments offer broad measurement ranges, yet exceptional sensitivity. They may be utilized for spot checks and for long-term trending of a variety of pressure measurement applications that require high reliability. Choose from the cutting edge AdvancedSense Pro, AdvancedSense BE or the new Zephyr III Meter (which replaces the workhorse “classical” Zephyr II in July 2020).

Differential pressure is a key HVAC measurement parameter in commercial, residential and institutional facilities and in manufacturing plants. For example, measuring pressure drop across coils and filters identifies when cleaning or replacement is in order, leading to improved occupant air quality and to significant energy savings. DP with a pitot tube can measure air velocities in difficult environments (e.g. stacks), over a very broad temperature range and up to very high velocities. DP monitoring is also a crucial parameter for determining pollutant pathways for IAQ (Indoor Air Quality) and for worker exposures, among many other applications.

AdvancedSense Pro/BE or Zephyr III

The auto-ranging DP-702LH sensor offers unparalleled accuracy plus range in a handheld meter.  

Either AdvancedSense meter, when purchased with optional built-in, auto-zeroing, differential pressure sensor options (standard with the Zephyr III), clearly displays pressure readings on its tactile, color screen. The auto-zeroing feature allows for highly accurate differential pressure logging over time. With a pitot tube, the unit provides direct air velocity or volume flow readings. The AdvancedSense Pro includes dual ‘K’-type thermocouple sockets for input from air, immersion, surface and other temperature probe configurations. 3 rugged sockets allow optional connection to any other GrayWolf probes for an extensive range of additional parameters. The dual K-type sockets are also standard on the Zephyr III, while optional on the AdvancedSense BE.

All three meters offer an easy-of-use, highly intuitive user interface. They include a broad range of advanced features such as attachment of text, audio, drawing or other note formats to logged data, on-board video help and on-site access to extensive educational information.

  • Auto-zeroing
    • Auto-cals zero every 2 minutes for excellent low range accuracy over hours/days/weeks of monitoring
  • DP-702LH (Auto-Ranging DP Sensors)
    • Range ±10,000Pa (40inH2O, 1000mmH2O, 100mBar, 70mmHg)
    • Resolution 0.1Pa (0.001inH2O, 0.01mmH2O, 0.001mBar, 0.001mmHg)
    • Accuracy (auto-zeroing enabled) ±1% of rdg ±0.1Pa up to 250Pa, ±1%rdg ±4Pa >250 (±1% of rdg ±0.001 inH2O to 1.000 inH2O, ±1%rdg ±0.015 inH2O>1.000)
  • Optional Air Velocity, Temperature, %RH
    • Connect standard or GrayWolf manufactured pitot tubes to display m/s, ft/min, l/s, cfm & more
    • Hot-wire air velocity probes; telescoping, articulating (and °C/°F)
    • Dual K Thermocouple sockets (optional only for AdvancedSense BE)
    • Optional Pt100 temperature/%RH probe
  • Back-lit color display
    • Clearly displays readings with a choice of unit symbols
    • View data in tabular or graphic formats
    • Tactile screen enhances ease-of-use
  • Data-logging
    • Manual “snapshot” or automatic “trend” data-logging
    • Store enhanced survey information on-site; data plus text, audio notes, photos/ videos (camera on AdvancedSense Pro only) and more…
  • Rugged Housing
    • Rubber side grips
    • Brass thread for wall bracket/tripod mounting, etc.
    • Optional instrument pouch with neck-strap
  • Intelligent user interface
    • Extremely easy-to-use
    • Intuitive icons and drop-down menus
    • Screen prompts user through operation
  • On-board educational tools
    • Feature tips, video help files (including several on how to use DP sensors)
    • Specific info for each sensor
    • Add your own procedures, field forms and more for on-site use
  • Reporting
    • Download logged data and notes to WolfSense® PC software (included) for analysis and efficient reporting
  • Expandable
    • Optional particle concentration (PM2.5, PM10, etc.) or particle count module (AdvancedSense Pro only)
    • Optional IAQ, toxic gas, VOC probes (AdvancedSense Pro/BE only)
    • Optional air velocity probes (hotwire and/or pitot static tubes)
    • Optional barometric pressure sensor
    • On-line (WiFi) data access (AdvancedSense Pro only) and much more…

Check out this brief overview of GrayWolf’s advanced Airspeed meters/instruments & how to organize a demonstration specific to your Air Velocity measurement needs

Additional Views

Front View of AdvancedSense Pro

Top View of AdvancedSense Pro

Bottom View of AdvancedSense Pro

Back View of AdvancedSense Pro


Classical Line Digital Micromanometer

Each Zephyr instrument incorporates an auto-zeroing, micromanometer and a ‘K’-type thermocouple socket for measuring differential pressure, static pressure and temperature. With a pitot tube, the Zephyr provides direct air velocity readings. Volumetric flow is calculated by simply entering the size of the duct and the instrument performs the necessary calculation. Zephyrs can also be fitted with a telescoping 3-function probe (model 2300 AHTS) to measure humidity, temperature and (hotwire) airspeed.

The Zephyr is a time tested, tried-and-true meter that has been utilized by many 1000s of clients over the last 15+ years. The large rubber grip and simple membrane switch pad ensure the unit is comfortable to use, allowing pushbutton operation even with gloves on. The 2300 AHTS probe attaches to the side of the instrument for single-handed operation.

The Zephyr is a stand-alone instrument with the ability to capture instantaneous snap-shot logs, or to trend log over time. Recorded data may be downloaded to WolfSense PC reporting and analysis software, which is included.

  • Standard inputs
    • Built-in, auto-zeroing, micromanometer (with broad range, yet excellent resolution)
    • ‘K’ type thermocouple
  • Optional probes
    • 3 function probe; hotwire airspeed, %RH, °C/°F
    • Pitot static tubes
    • Surface, immersion, penetration, air temperature
  • Large and clear display
    • Measure up to 16 variables simultaneously
    • Scroll through readings on display
    • Automatically updated when probes plug in
    • On screen instructions for easy operation
  • Data port (II+ model only)
    • Allows logged data to be downloaded to spreadsheet for analysis (USB data cable included)
    • Manual or automatic datalogging available
    • Advanced datalogging for unattended surveys
  • Intuitive menu system
    • Minimum training required
    • Easy-to-use
    • Screen prompts guide user through operation
  • Easy access to batteries
    • Disposable or rechargeable can be used
    • AC power adapter available
  • Durable housing
    • Impact resistant
    • Comfortable to use
    • Large rubber grip and hand strap
    • Single-handed operation

Optional, telescoping 2300AHTS 
3-function T/RH/Airspeed probe 
can be fixed to the side of 
the Zephyr digital micromanometer

Standard Zephyr Kits

Click below to download PDF Brochures:

Application Notes

Download “Aircraft Maintenance Differential Pressure Kit”

For Detailed Information: