Kestrel 5400 Heat Stress Tracker Kestrel 5400 Heat Stress Tracker Kestrel 5400 Heat Stress Tracker Kestrel 5400 Heat Stress Tracker
5-Year Warranty on all Kestrels

Kestrel 5400 Heat Stress Tracker

Product code: K5400 - 0854

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£-- inc. VAT (from £ ex VAT)

LiNK Wireless Dongle (for PC or Mac) @ £ ex VAT)
USB Data Transfer Interface @ £ ex VAT)

Most user-friendly WBGT meter on the market. Detect when heat-related conditions are unsafe well before your body does.

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Quick Look

• Measures Wet Bulb Globe Temperature (WBGT), Thermal Work Limit (TWL), heat index, temperature, humidity and much more. 15 measurements in all!
• Waterless! Natural Wet Bulb Temperature accurately calculated from on-board digital sensors with no tedious setup or maintenance.
• Large, hi-res, hi-contrast, graphic display is perfectly readable in the brightest sunlight and is backlit for use in low-light conditions.
• Handheld, portable, data logger with customizable warning flag settings, graphing and measurement statistics.
• Optional LiNK connectivity powered by Bluetooth Smart® provides wireless communication to mobile devices and computers.
• Rugged (drop tested to MIL-STD-810G standards), waterproof (sealed to IP67 standards) and floats.
• Protective pouch, neck lanyard and Lithium AA battery included.
• 5-year warranty.


The next generation of WBGT and environment monitoring is the here with the Kestrel 5400 Weather Meter.

The Kestrel 5400 provides the same trusted accuracy, reliability, and usability as the original Kestrel 4400 and 4600. The Kestrel 5400 is a handheld, portable, WBGT (Wet Bulb Globe Temperature) measurement tool and environmental data logger. No need for distilled water, bulky globes, complicated setup or expensive equipment. Getting accurate measurements couldn't be easier: just hold the Kestrel Heat Stress Tracker in the area of interest for both instantaneous and average WBGT measurements. Set the appropriate WBGT thresholds for flag warnings and the loud buzzer, bright LED beacon and on-screen warnings provide instant notification of dangerous conditions. Plus the Kestrel 5400 comes with commonly used heat safety guidelines on a handy, waterproof chart.

Unlike other WBGT meters on the market, the Kestrel 5400 is a full-featured weather meter as well. Measure wind speed, maximum wind gusts, temperature, humidity, pressure, wind chill, density altitude and more. No matter what your activity, the Kestrel 5400 provides insight into the critical conditions affecting safety, performance and success. The Kestrel 5400 with LiNK wireless data communication adds a compass for tracking wind direction as well, expanding its usability to include HAZMAT response, and even measuring headwind at the running track!

The new Kestrel 5 Series platform adds many new features and options. If you're familiar with the Kestrel 4400 or 4600, the first thing you'll notice is the larger, higher-resolution and contrast display and improved font readability. The Kestrel 5 series also includes a built-in dual color backlight, extra-strong polycarbonate lens and AA battery operation and offers optional LiNK iOS and Android wireless connectivity and app support. Like all Kestrel meters, the Kestrel 5400 is drop-proof, dust-proof, waterproof and able to withstand harsh environments without damage – so it can be used anywhere needed to keep athletes, workers, military personnel and animals safe from heat injury. A range of carry pouch options makes it even easier to take your Kestrel meter with you.

Pair the Kestrel 5400 with the optional Kestrel Vane Mount for hands-free measurements over the course of the practice, training session or workday. And for maximum functionality, choose the Kestrel 5400 with LiNK to transmit live measurements to your phone or tablet when you're within range. The Kestrel LiNK app will also display alerts on your mobile device to let you know when conditions have become dangerous.

In addition to measuring the current environmental conditions, the Kestrel 5400 tracks and logs over 10,000 sets of time-stamped data. Your data log can be transferred to a mobile device wirelessly with the LiNK wireless communication option and Kestrel LiNK app, or to a PC with either the accessory Kestrel LiNK Dongle or waterproof USB Data Transfer Cable (available separately).

Kestrels have been put to the test in some of the harshest conditions on the planet. U.S. Special Forces, combat weather teams, wildland firefighters, smoke jumpers, Mt. Everest expeditions and auto pit crews are just a few who rely on a Kestrel to provide them with the crucial environmental data they need. The Kestrel Heat Stress Tracker line has been used by the US Army, US Navy, athletic trainers, and even organizers at the Boston Marathon. There truly is no comparable environmental safety monitoring tool on the market. Adopt best safety practices for your team or workplace and add a Kestrel Heat Stress Tracker to your toolkit.

What's New in the Kestrel 5400

Kestrel LiNK for mobile

Android and iOS apps put crucial information at your fingertips with real-time remote data viewing on phones and tablets up to 100' away. Kestrel LiNK also provides easy data export, threshold alerts and simple firmware updates.

LiNK wireless connectivity powered by Bluetooth Smart

Robust, easy connectivity to both iOS and Android mobile devices as well as PCs.
(Computers require optional Kestrel USB Dongle.)

USB Data Transfer Cable

Low profile, lightweight, waterproof cable provides wired connectivity to Windows and Mac computers for fast data uploads and firmware updates. Compatible with every model in the Kestrel 5 Series.

Sleek, rugged tripod vane mount

Small, secure, robust vane mount turns any Kestrel 5 Series meter into a portable weather station that remains oriented into the wind.
(Included in some models where noted, otherwise sold as optional accessory.)

Large, high contrast screen

Easily readable text in almost any setting, including bright sunlight, with more visible information on the screen at all times. This high-resolution display is easy on the eyes, allowing you to get more information from customizable user screens, charting and graphing options without causing eye strain or fatigue.

Dual color backlight

Toggle backlight color between standard white and night-vision-preserving red (NV). The red NV backlight features an optical wavelength selected to help users sustain natural night vision and reduced brightness to avoid detection during night maneuvers.

Secure battery door

Large, O-ring sealed door provides easy, tool-free battery access.

Scratch and breakage-resistant window

Rigid, polycarbonate lens with scratch-coating protects the display from damage.

Corrosion-resistant battery compartment

Battery is isolated from electronics, reducing damage in the event of a battery leak.
(Note – Lithium AA batteries strongly recommended to avoid battery leakage altogether.)

Intuitive user-interface

Icon-based navigation, intuitive keypad, and multiple languages make the Kestrel a breeze to use.


• Altitude
• Barometric Pressure
• Density Altitude
• Dew Point Temperature
• Globe Temperature
• Heat Stress Index
• Naturally Aspirated Wet Bulb Temperature
• Relative Humidity
• Station Pressure (Absolute Pressure)
• Temperature
• Thermal Work Limit (TWL)
• Wet Bulb Temperature (Psychrometric)
• Wet Bulb Globe Temperature (WBGT)
• Wind Chill
• Wind Speed

Sensor Accuracy (+/-) Resolution Specification Range Notes
Wind Speed | Air Flow Larger of 3% of reading, least significant digit or 20 ft/min 0.1 m/s
1 ft/min
0.1 km/h
0.1 mph
0.1 knots
1 B*
0.1 F/S*
0.6 to 40.0 m/s
118 to 7,874 ft/min
2.2 to 144.0 km/h
1.3 to 89.5 mph
1.2 to 77.8 knots
0 to 12 B*
1 inch|25 mm diameter impeller with precision axle and low-friction Zytel® bearings. Startup speed stated as lower limit, readings may be taken down to 0.4 m/s | 79 ft/min| 1.5 km/h | .9 mph | .8 kt after impeller startup. Off-axis accuracy -1% @ 5° off-axis; -2% @ 10°; -3% @ 15°. Calibration drift < 1% after 100 hours use at 16 MPH | 7 m/s. Replacement impeller (NK PN-0801) field installs without tools (US Patent 5,783,753). Wind speed calibration and testing should be done with triangle on impeller located at the top front face of the Kestrel. Measuring wind speeds above 60 m/s / 134.2 mph can damage the impeller.
*F/S only in Ballistics units. Beaufort not available in Ballistics units.
Ambient Temperature 0.9 °F
0.5 °C
0.1 °F
0.1 °C
-20.0 to 158.0 °F
-29.0 to 70.0 °C
Airflow of 2.2 mph|1 m/s or greater provides fastest response and reduction of insolation effect. For greatest accuracy, avoid direct sunlight on the temperature sensor and prolonged sunlight exposure to the unit in low airflow conditions. Calibration drift is negligible for the life of the product. For further details, see Display & Battery Operational Temperature Limits
Relative Humidity ±2%RH 0.1 %RH 10 to 90% 25°C non-condensing To achieve stated accuracy, unit must be permitted to equilibrate to external temperature when exposed to large, rapid temperature changes and be kept out of direct sunlight. Calibration drift is typically less than ±0.25% per year.
Pressure ±1.5 mbar at 25°C, 700-1100 mbar/ ±0.044inHg at 77°F 20.67-32.48 inHg/
±0.022 PSI 10.15-15.95 PS
0.01 inHg
0.1 hPa|mbar
0.01 PSI
700-1100 mbar/20.67-32.48 inHg/10.15-15.95 PSI
Monolithic silicon piezoresistive pressure sensor with second-order temperature correction. Between 1100–1200 mbar, unit will operate with reduced accuracy. Sensor may not operate above 1200 mbar and can be damaged above 6,000 mbar or below 10 mbar. Calibration drift is negligible for the life of the product.
Compass ±5°
1/16th Cardinal Scale
0 to 360° 2-axis solid-state magnetoresistive sensor mounted perpendicular to unit plane. Accuracy of sensor dependent upon unit's vertical position. Self-calibration routine eliminates magnetic error from batteries or unit and must be run after every full power-down (battery removal or change). Readout indicates direction to which the back of the unit is pointed when held in a vertical orientation. Declination/variation adjustable for True North readout.


Calculated Measurements

Measurement Accuracy (+/-) Resolution Sensors Deployed
Air Density 0.0002 lb/ft3
0.0033 kg/m3
0.001 lbs/ft3
0.001 kg/m3
Temperature Relative
Humidity Pressure
Air Flow 6.71% 1 cfm
1 m3/hr
1 m3/m
1 L/s
Air Flow
User Input (Duct Shape & Size)
Altitude typical: 23.6 ft/7.2 m - 50 to 1100 mBar
max: 48.2 ft/14.7 m – 300 to 750 mBar
1 ft
1 m
User Input (Reference Pressure)
Barometric Pressure 0.07 inHg
2.4 hPa|mbar
0.03 PSI
0.01 inHg
0.1 hPa|mbar
0.01 PSI
User Input (Reference Altitude)
Crosswind & Headwind / Tailwind 7.1% 1 mph
1 ft/min
0.1 km/h
0.1 m/s
0.1 knots
Wind Speed Compass
Delta T 3.2 °F
1.8 °C
0.1 °F
0.1 °C
Temperature Relative
Humidity Pressure
Density Altitude 226 ft
69 m
1 ft
1 m
Temperature Relative
Humidity Pressure
Dew Point 3.4 °F
1.9 °C
15-95% RH. Refer to Range for Temperature Sensor
0.1 °F
0.1 °C
Temperature Relative
Evaporation Rate 0.01 lb/ft2/hr
0.06 kg/m2/hr
0.01 b/ft2/hr
0.01 kg/m2/hr
Wind Speed Temperature Relative Humidity Pressure User Input (Concrete Temperature)
Heat Index 7.1°F
0.1 °F
0.1 °C
Temperature Relative Humidity
Moisture Content | Humidity Ratio (“Grains”) .3gpp
0.1 gpp
0.01 g/kg
Temperature Relative Humidity Pressure
Relative Air Density 0.3% 0.1% Temperature Relative Humidity Pressure
Wet Bulb Temperature - Psychrometric 3.2 °F
1.8 °C
0.1 °F
0.1 °C
Temperature Relative Humidity Pressure
Wind Chill 1.6 °F
0.9 °C
0.1 °F
0.1 °C
Wind Speed Temperature


Additional Product Info

Display & Backlight Multifunction, multi-digit monochrome dot-matrix display. Choice of white or red LED backlight.
Response Time & Display Update Display updates every 1 second. After exposure to large environmental changes, all sensors require an equilibration period to reach stated accuracy. Measurements employing RH may require longer periods particularly after prolonged exposure to very high or very low humidity.
Data Storage & Graphical Display, Min/Max/Avg History Logged history stored and displayed for every measured value. Manual and auto data storage. Min/Max/Avg history may be reset independently. Auto-store interval settable from 2 seconds to 12 hours, overwrite on or off. Logs even when display off except for 2 and 5 second intervals. Kestrel 5 series units hold over 10,000 data points.
Data Upload & Bluetooth® Data Connect Option Wireless range up to 100ft. Connection requires optional USB data transfer cable or Kestrel Link Dongle or Kestrel LiNK app. Employs Kestrel Link protocol for data transmission with Link supported devices. (Kestrel LiNK for iOS/Android, Kestrel Link for PC/MAC).
Clock / Calendar Real-time hours:minutes:seconds clock, calendar, automatic leap-year adjustment.
Auto Shutdown User-selectable – Off, 15-60 minutes with no key presses.
Languages English, French, German, Spanish.
Certifications CE certified, RoHS and WEEE compliant. Individually tested to NIST-traceable standards.
Origin Designed and manufactured in the USA from US and imported components. Complies with Regional Value Content and Tariff Code Transformation requirements for NAFTA Preference Criterion B.
Battery Life AA Lithium, included. Up to 400 hours of use, reduced by backlight or Bluetooth radio transmission use.
Shock Resistance MIL-STD-810g, Transit Shock, Method 516.5 Procedure IV; unit only; impact may damage replaceable impeller.
Sealing Waterproof (IP67 and NEMA-6)
Display & Battery Operational Temperature Limits 14° F to 131° F | -10 °C to 55 °C Measurements may be taken beyond the limits of the operational temperature range of the display and batteries by maintaining the unit within the operational range and then exposing it to the more extreme environment for the minimum time necessary to take reading
Storage Temperature -22.0 °F to 140.0 °F | -30.0 °C to 60.0 °C.
Size & Weight 5.0 x 1.9 x 1.1 in / 12.7 x 4.5 x 2.8 cm, 4.3 oz / 121 g. (Lithium battery included)

Compatible Software Apps

Kestrel LiNK for Windows

Simple communication to Windows computers is provided through the optional LiNK .USB Dongle or USB Data Transfer Cable. Download your data to view, analyze and archive. Enables firmware update of Kestrel 5 series meters.

DOWNLOAD KESTREL LINK FOR WINDOWS v 1.04 (Last Updated 28th November 2016)
Compatible with Windows 7, Windows 8, Windows 8.1, and Windows 10

Kestrel LiNK for Android

Wireless connection. When in range, view real-time measurements, receive on-screen alerts and download your data. Logged data can be viewed, analyzed, archived and shared via e-mail, Facebook and Twitter.
Enables firmware update of Kestrel 5 series meters.
NOTE: Range up to 100' line of sight – reduced by walls and obstructions.

Kestrel LiNK for iOS

Wireless connection. When in range, view real-time measurements, receive on-screen alerts and download your data. Logged data can be viewed, analyzed, archived and shared via e-mail, Facebook and Twitter.
Enables firmware update of Kestrel 5 series meters.
NOTE: Range up to 100' line of sight – reduced by walls and obstructions.

Kestrel LiNK for OSX (Mac)

Transfer data from your Kestrel 5 Series device and archive on your Mac computer. Data logs can be exported as csv files for viewing and analysis in spreadsheets. This software also facilitates updates and upgrades to your device firmware.

DOWNLOAD KESTREL LINK FOR MAC v 1.04 (Last Updated 28th November 2016)

Models & SKUs

• Kestrel 5400 Heat Stress Tracker (Orange): 0854ORA
• Kestrel 5400 Heat Stress Tracker (Tan): 0854TAN
• Kestrel 5400 Heat Stress Tracker + Vane Mount (Orange): 0854VORA
• Kestrel 5400 Heat Stress Tracker + Vane Mount (Tan): 0854VTAN
• Kestrel 5400 Heat Stress Tracker Pro with Compass and LiNK + Vane Mount (Orange): 0854LVCORA
• Kestrel 5400 Heat Stress Tracker Pro with Compass and LiNK + Vane Mount (TAN): 0854LVCTAN


• Neck Lanyard
• AA Lithium Battery (Average Life 400 Hours)
• Protective Drawstring Pouch
• Certificate of Conformity (with complete specifications)
• Instruction Manual
• Five Year Warranty

Customer Support