COVID-19 Response

St. Croix Sensory remains open and committed to the success of your project needs throughout the COVID-19 pandemic.

For the safety of our clients and staff, we have outlined our “Best Practice Recommendations” for the use and care of the Nasal Ranger Field Olfactometer, Odor Sensitivity Test Kit and odor sampling equipment.


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Nasal Ranger - Field Olfactometer

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Measure Odors with Precision
The Nasal Ranger provides a precise odor strength measurement that is consistent from place to place.
Truly Easy Odor Measurement
No only easy to use, the Nasal Ranger epitomizes user-friendly. The Nasal Ranger also opens doors and created interest in community odor issues.
The Nasal Ranger Package
The Nasal Ranger - Nasal Mask - Comfort Seals (10pk) - Mask Wipes (10pk) - Universal Odor Filter Cartridges (2 pair) - Barrel Cleaning Brush - Operations Manual - Calibration Certificate
Portability & Ease of Use
The Nasal Ranger allows the facility to quantify odors around the perimeter in the surrounding community.
Essential Tool
The Nasal Ranger offers an innovative easy-to-use alternative to guessing odor strength.
Universal Odor-Filter Cartridges
Easy to replace odor-filter cartridges contain a proprietary blend of granular carbon to create odor-free dilution air.
Dilution-to-Threshold (D/T)
Quantify odor strength using standard D/T ratios: 60, 30, 15, 7, 4, and 2
Custom D/T Nasal Ranger Dials
High D/T Dials (500, 400, 300, 200, 100, and 60) and custom ratios for your needs.
Evaluate Odor Mitigation
With the Nasal Ranger you can evaluate odor mitigation methods and control effectiveness.
Nasal Mask
Teflon coated carbon-fiber epoxy, ergonomically designed to fit your nose comfortably with a foam comfort seal.
Fun and approachable
Operating the Nasal Ranger is easy enough for a child!
Calibrated for Accuracy
The Nasal Ranger uses a calibrated flow sensor to assure users a consistent inhalation rate.
Community Odor Monitoring
With the Nasal Ranger, you can investigate citizen odor complaints for determining odor sources.
Confidently determine odor with the Nasal Ranger at operations under compliance surveillance.
Create Credible, Defensible Evidence
Monitoring daily industrial operations on odor patrols, the Nasal Ranger documents baseline conditions and specific odor episodes.
Internationally Accepted
Throughout North America, South America, Africa, Europe, Asia, and Australia...
The Nasal Ranger successfully determined odor annoyance thresholds.

Nasal Ranger is the “state-of-the-art” in field olfactometry for confidently measuring and quantifying odor strength in the ambient air. The portable Nasal Ranger Field Olfactometer determines ambient odor Dilution-to-Threshold (D/T) concentration objectively with your trained nose.

The Nasal Ranger Package includes the Nasal Ranger with Nasal Mask, Odor-Filter Cartridges, Shoulder Strap, Carrying Case, as well as and extra pair of Odor-Filter Cartridges, 10-Comfort Mask Seals, and 10-Isopropyl Alcohol Mask Wipes.


– Precision instrument for measuring ambient-odor
    Dilution-to-Threshold (D/T).

– Portable odor detecting and measuring –
    Scentometer, US-EPA protocol.

– Discrete calibrated dilution ratios:
    standard and custom ranges available.

– Inhalation Rate “feed-back” for 16-20 liters per minute
    calibration range.

– Easy to change odor filter cartridges.

– Ergonomic, comfortable sniffing mask with inhale & exhale ports.


Preparation = Success

St. Croix Sensory recognizes each odor monitoring project has unique needs.  To ensure your project has confident inspectors who collect odor data with accuracy and ease, consider the following questions when assembling your Nasal Ranger order and review the information in the tabs below.

1. How many investigators will be on your team?

2. How will you qualify your team to investigate odors?

3. How often will you monitor odors?

4. What is your odor study application?

 5. How will you collect and store your odor monitoring data?

Whether you have one designated odor investigator or an entire team, we recommend everyone who uses the Nasal Ranger Field Olfactometer has the proper equipment, qualifications and training.

The Nasal Ranger Package

Each Nasal Ranger package includes the Nasal Ranger unit with Nasal Mask, Odor-Filter Cartridges, Shoulder Strap, Carrying Case, an extra pair of Odor-Filter Cartridges, 10-Comfort Seals, 10-Isopropyl Alcohol Mask Wipes, 1 training access code to our on-line training course, “Nasal Ranger Inspector” and a 6-month subscription to our on-line odor mapping app, Odor Track’r®.

Nasal Ranger Mask Package

The Nasal Ranger successfully measures odorous air by creating an air-tight seal between the Nasal Ranger mask and the investigator.  To ensure every user has a proper fit, we recommend each odor investigator is assigned their own mask.

Each Nasal Ranger Mask Package includes: a mask, 10-Comfort Seals, and 1 online training access code for the “Nasal Ranger Inspector” course.


A trained inspector is a successful inspector. St. Croix Sensory offers many options to fit your unique training needs.  From online courses to on-site instruction, contact us for more details. 

Our online “ODOR SCHOOL”® training course, “Nasal Ranger Inspector” is a comprehensive and flexible training option for one or many.  Register and train from the comfort of your own location, at your own pace. A “Certificate of Completion” is generated for each student who passes the final exam.  Lean More!

Odor Sensitivity Test Kit

Make Sure your investigators are certified with proper olfactory sensitivity.

ODOR SCHOOL”® Training

A trained inspector is a successful inspector. St. Croix Sensory offers many options to fit your unique training needs.

Our online “ODOR SCHOOL”® training course, “Nasal Ranger Inspector” is a comprehensive and flexible training option for one or many.  Register and train from the comfort of your own location, at your own pace. A “Certificate of Completion” is generated for each student who passes the final exam.

See more in our Sensory Institute

The frequency of your odor monitoring project will determine how many cartridges and comfort seals you will want to have on hand throughout your project.


The life of the odor-filter cartridge will depend on how often it is used and the strength of the odors that it is filtering.  A reasonable rule-of-thumb is to replace the cartridge pair after 200-hrs of field use.  Stronger odors may require more frequent replacement.

Cartridges are sold by the pairs or by the case (6 pair).

Comfort Seals

Comfort seals ensure an air-tight fit between the Nasal Ranger mask and the user.  We recommend the comfort seal is wiped down after each use, replaced between users, or replaced between 2-4 uses by the same user.

The Standard D/T Dial and the Universal Cartridges are included with each Nasal Ranger package, but Nasal Ranger accessories can be customized for your specific application.


If you are monitoring strong odors close to the property line or on-site, you will want to consider the High D/T Dial with odor concentrations ranging from 60-500D/T.

Standard D/T Dial:  60, 30, 15, 7, 4, and 2 D/T

High D/T Dial: 500, 400, 300, 200, 100, and 60 D/T

Specialty and Custom D/T Dials are available.  Inquire with us.


in addition to the Universal Cartridge, you may want to order a cartridge type specific to your industry odors.  St. Croix Sensory offers four types of cartridges for your odor monitoring needs:

Type I: Universal Cartridge

Type II: Organic Vapor Cartridge: Highly concentrated solvents, paint, etc.

Type III: Hydrogen Sulfide: Sulfur gases, swine/cattle facilities, wastewater, landfills

Type IV: Ammonia/Nitrogen Compounds: Poultry facilities

Make sure your odor data is collected in a safe and helpful manner.  Each Nasal Ranger package includes a 6-month subscription to Odor Track’r®, our online data mapping application. Subscriptions can be renewed as needed.

Odor Track’r®

Collect, record and archive odor data with ease and reliability in the field with this easy to use application.  Generate reports to share with officials and management.

Kestrel Weather Meter

Weather conditions play a key role in odor episodes and are important to monitor in your project.  Collect the detailed weather data you need with a Kestrel Weather Meter and accessories.

Standard Dilution-to-Threshold (D/T) Ratios:   2, 4, 7, 15, 30, and 60

High Range D/T Ratios available:   60, 100, 200, 300, 400, and 500

Custom D/T Ratios available to your needs.

Accuracy:   +/- 10% Calibration

Weight:  2.0-lbs  (0.91 kg)

Dimensions:  14″ L x 7.5″ H x 4″ W  (35.5 x 19 x 10 cm)

Inhalation Rate:  16-20 LPM

Operating Range:  32 to 104F,  0 to 40C

Power Requirements:  Standard 9-Volt battery

Patent: U.S. Patent No. 6,595,037

EMC Verification: Emissions: EN61326:1997, Class B
                                  Immunity: EN61326:1997, Industrial Location

Markings: CE 89/336/EEC (EMC); 92/59/EEC (General Safety)

Q: Where can I buy a Nasal Ranger?
The Nasal Ranger may be purchased by contacting St. Croix Sensory  directly, or contact an authorized Nasal Ranger representative found at the link below.

Q: What does the Nasal Ranger measure?
The Nasal Ranger Field Olfactometer quantifies the perceived odor level as dilutions-to-threshold (D/T).  This is determined as the number of dilution needed to make the ambient air odor just detectable.

Q: Who can use the Nasal Ranger?
Almost anyone can use the Nasal Ranger!  Commonly, air quality control managers, municipality managers and regulators, facility operators, and citizen groups are using the Nasal Ranger to quantify ambient odors.

Q: How often do I need to change the odor filter cartridge?
The life of the odor filter cartridge will depend on how often it is used and the strength of the odors that it is filtering.  A reasonable rule-of-thumb is to replace the cartridge after 200-hrs of field use.  Stronger odors may require more frequent replacement.  Please see this video (right) for additional information and demonstration of the filter replacement.

Q: What is the difference between Field Olfactometry and Laboratory Olfactometry?
Both threshold results are based on the dilution-to-threshold principle and are thus a similar measure.  Laboratory olfactometry, following ASTM E679 and EN13725, is best utilized when source odors are being measured (e.g. source stack emission).  Air dispersion modeling is then utilized to predict the impact of those source odors on the community.  Field Olfactometry is performed to quantify the odors in the community; therefore, it is a direct measure of the community impact at that specific moment in time.

Q: How frequently should my Nasal Ranger be calibrated?
The Nasal Ranger should be sent to St. Croix Sensory for annual calibration verification.

Nasal Ranger Product Brochure (pdf)

Operations Manuals

Nasal Ranger Field Olfactometer Operations Manual v7.1 (pdf)   [English]

Nasal Ranger Olfactómetro de Campo Manual de Operacion (pdf)   [Spanish]

Nasal Ranger Olfactometre de Terrain Manuel Utilisateur (pdf)   [French]

Nasal Ranger Przenośny Odoromierz Instrukcja dla Użytkownika (pdf)   [Polish]

Published Papers 

MORE Published Papers and Articles in our Library!

Authorized International Representatives

Stephenson Environmental Management Australia

Sydney, NSW





Hong Kong


Odosys Solutions

Selangor, Malaysia
S.E. Asia

(Singapore, Malaysia, Thailand, Indonesia, Philipines)


South Korea

Crestwood Environmental Ltd.

Wolverhampton, England
United Kingdom

(England, Scotland, Ireland, Isle of Man, and Channel Islands)





Tigret S.p. z o.o.





Import Trading, S.A.

Montevideo, Uruguay
South America

(Argentina, Brazil, Paraguay, Uruguay)



MENA Region
(UAE, Saudi Arabia, Qatar, Kuwait, Yemen, Egypt, and Bahrain)

Top Notes from the Lab