Kestrel Heat Stress Monitoring System


Ensure worker safety & regulatory compliance with the Kestrel® Heat Stress Monitoring System. With real-time remote access to critical data, leaders have the information to make timely decisions to prevent workplace heat-related injuries and incidents. The Kestrel 5400 Heat Stress Tracker with LiNK wirelessly connects via Bluetooth to the easy-to-read, wall-mounted remote monitoring tablet showing current data. Use the Kestrel LiNK app to manage and log work conditions, view graphs, and create shareable reports.

Stay aware of real-time workplace conditions even when you’re offsite. The Ambient Weather Network (AWN) cloud-based online portal and app offers remote monitoring capabilities for 24-7 visibility, including a custom dashboard for tracking weather data and the ability to set alerts for changing conditions.

Works with AWN, the Ambient Weather Network
Availability: In stock


Kestrel Heat Stress Monitoring System Overview

Improve the safety of your employees and comply with OSHA regulations with remote monitoring for heat index and WBGT.

Protect workers from extreme working conditions with this simple-to-deploy and highly accurate heat index and WBGT meter, and remote monitoring tablet.

The Kestrel Heat Stress Monitoring System is an accurate yet simple solution to help leaders and managers identify and mitigate heat stress and heat-related illnesses among workers in any indoor or outdoor job site environment.

Avoid hourly wage loss due to exertional heat-related illness. Drive OSHA reported heat Stress events down to zero with our simple integrated system.

  • Cloud + Device-based records of environmental conditions.
  • Report tracking made easy for compliance with OSHA guidelines.
  • Avoid lost time and maximize work time.
  • Avoid hourly wage loss due to exertional heat-related injury/sickness.
  • Reduce worker’s comp and insurance claims.

Stay Connected to Your Data

With the Kestrel LiNK app, you can easily view data from your connected 5400 Heat Stress Tracker for onsite conditions on your remote monitoring tablet or a mobile device via Bluetooth. However, if you need to view job site conditions remotely while you're not physically onsite, you can log in to the cloud-based platform Ambient Weather Network online or on the AWN app. AWN allows you to view, track, and log all job site conditions, helping safety managers stay informed and alert to dangerous working conditions no matter where they are.

Display Jobsite Conditions on the Included Tablet with Kestrel LiNK

Monitor onsite conditions at a glance

Ambient Weather Network (AWN) Makes Remote Data Access Simple & Convenient

View current workplace conditions even when you're offsite.

Benefits of the Kestrel Heat Stress Monitoring System

  • Complies with OSHA National Emphasis Program for heat stress monitoring.
  • Live remote monitoring to ensure safer conditions and log data to comply with OSHA guidelines
  • Monitor heat stress and log conditions for occupational work sites with audible, text, and email alerts.
  • The Kestrel Heat Stress Pro Meter can be used as stand-alone system.

Included In This Bundle

  • Kestrel 5400 HST Pro w Compass + LiNK
  • Kestrel Remote Monitoring Tablet
  • Certificate Of Conformity (Spec Sheet)
  • Heat Stress Reference Card(Waterproof)
  • Instructions
  • Battery - 1 x AA lithium battery
  • Lanyard
  • AC Adapter
  • Mounting Hardware
  • K5 Protective Soft Case

Currently for United States customers only. Universal AC Adapter coming soon.

Tablet Specs

System CPU RK3399 Dual-core A72 + quad-core A53
Internal Memory 16GB
Operating System Android 10.0
Display Touch Screen 10-Points Capacitive Touch Screen
Panel 10.1"LEDIPSpanel
Resolution 1280x800
Active area 218(H)x136.5mm(V)
Contrast ratio 800:1
Luminance 300cd/m2
Aspect Ratio 16:9
Network Wifi 802.11b/g/nac2.4G&5G
Ethernet 100M/1000M
Bluetooth Bluetooth 4.2
Interface Card slot SD, Support up to 64GB
USB USB2.0*1 USB3.0*1
USB USB for serial (RS232 format)
Micro USB Micro USB OTG
HDMI HDMI output
RJ45 RJ45 (with PoE function, IEEE802.3at, POE+, class 4,25.5W)
Power jack DC power input
Earphone 3.5mm earphone
Media Play Video Format MPEG-1, MPEG-2, MPEG-4, H.263, H.264, VC1, RVetc., support up to 4K
Audio Format MP3/WMA/AAC etc.
VESA 75x75mm
Speaker 2*2W
Camera 2.0M/P, Front camera
Microphone Built-in
Working temp 0-50 degree
AWN max upload refresh rate As fast as once per minute
Language Multi-language
Accessories Adapter Adapter, 12V/2A
User manual Yes

Product Questions

"All measurements not available in all units"

Temperature Functions

For best accuracy when taking temperature measurements you must keep the air moving around the temperature sensor and keep the Kestrel out of prolonged, direct sunlight. If there is a strong breeze, just point the Kestrel into the wind. If there is no wind, swing the Kestrel around in a circle on its lanyard or rapidly wave it back and forth in hand. This ensures that the sensor measures the temperature of the air rather than the temperature of the case. Alternatively, if you have time, allow the Kestrel to rest where you want to measure the air temperature (NOT in your hand or in direct sunlight if there is no wind) until the case temperature equalizes with the air temperature. When equalized, the display will read a constant value. Be aware that this could take a few minutes, particularly if there is no wind.

Humidity Functions

One reason your Kestrel may not be reading accurate ambient humidity is because of proximity to humidity sources such as your hand, your body or the ground. Avoid covering the large humidity chamber opening on the case rear with your fingers. Keep all fingers below the finger groove and away from the chamber opening. Do not take reading that rely upon humidity with the Kestrel meter lying flat – raise it into the air vertically or stand it on its base and orient it into the wind or air flow. If a high level of accuracy is required for measurements involving humidity, do not hold the unit while taking measurements. Taking readings with the Kestrel in your hand or over your body can raise relative humidity by 5% or more. A Kestrel vane mount will isolate the Kestrel Meter from erroneous humidity influences and keep it oriented into the wind or air flow while taking measurements. Whenever you move your Kestrel Meter into a new environment wait until the primary sensor values have stabilized (Temperature, Humidity, etc.) before taking measurements that rely upon these values. After a large change in environmental condition, this may take 15 minutes or more, with humidity potentially taking the longest. If the humidity sensor housing (located above the rear label) is wet, the Kestrel cannot take an accurate humidity reading. If the sensor does become wet, shake the unit vigorously to remove the water, and then let it dry completely before use. If the sensor comes in contact with salt water, rinse it thoroughly with clean water, then shake it and allow it to dry. As is typical with humidity sensors, it is possible for the humidity sensor in the Kestrel to drift over time as described in the spec sheet. If your unit has a Humidity recalibration function, it can be returned to the factory or used with the Kestrel RH Calibration Kit to recalibrate its humidity readings.

Wind Meter Functions

Wind speed is highly dependent on surrounding obstructions such as buildings, yourself and the ground, with wind speeding up as it flows around and over obstacles and slowing down as it passes behind them. Even in an open area, Wind speed will be slower near the ground so ensure you are taking measurements at an appropriate height for your application. Hold the back of the unit directly into the wind. Holding the unit off-axis by 5° will reduce accuracy by 1%, 10° will reduce accuracy by 2% and 15° will reduce accuracy by 3%. Using a Kestrel Vane Mount will ensure the unit is correctly oriented into the wind and measuring accurate wind speeds. The Kestrel impeller housing can rotate in the unit. For best accuracy, ensure one of the three “arms” of the impeller housing is pointing straight up. The wind speed displayed by the Kestrel Meter is a 3 second rolling average. This allows the unit to provide a value that is more representative of the typical, ambient conditions but not capture peak speeds for instantaneous blasts of air.

Compass Functions

The compass in the Kestrel Meter is used for direction, crosswind, headwind/tailwind as well as for capturing various user inputs based on direction. When calibrating and when using the compass, it is important to hold the unit as vertically as possible. Any tilt in angle present when the unit is calibrated or when measurements are taken will negatively impact the accuracy of the compass reading. Many users will inadvertently tilt the Kestrel Meter away from themselves slightly when holding the unit. If a high level of accuracy is required, using a Kestrel vane mount on a leveled tripod for calibration and measurement can eliminate error.

Pressure Functions

All pressure and altitude measurements are made using the pressure sensor. Some units have a dedicated “Pressure” screen which shows Station Pressure, the raw pressure reading straight from the sensor. The Barometric Pressure measurement (Baro) displays the local Barometric Pressure using the Station Pressure measurement adjusted to the local altitude using the Reference Altitude value input by the user. The Altitude measurement displays the local altitude using the Station Pressure measurement combined with the Reference Baro value input by the user. To obtain an accurate barometric pressure or altitude readings, you must first know EITHER your location’s current barometric pressure OR your current altitude. If the Reference Altitude value is incorrect, the Barometric Pressure reading will also be incorrect. If the Reference Barometric pressure value is incorrect, the Altitude reading will also be incorrect. Because Barometric Pressure and Altitude are each dependent on the alternate reference value remaining constant, Barometric Pressure and Altitude cannot be accurately measured simultaneously. If your unit has a pressure recalibration function, a new Barometric Pressure calibration value may be input. If this value was not taken from a verified source (a local airport or weather station) with the Kestrel being calibrated at the same location as the reference device, pressure related measurements may be incorrect.


When changing environments (such as moving form an air conditioned room to outdoors or removing the unit from your pocket) the unit requires between 8-15 minutes to equilibrate to its surroundings before taking readings. Take measurements at least 3 feet off the ground and in the same wind or air flow conditions as the people you are monitoring. Ensure the Kestrel is oriented into the wind and able to measure the full wind value. A tripod or pole mount and the Kestrel Rotating Vane Mount are ideal for ensuring accurate measurements. Differences in the reflectivity of ground surfaces such as grass or asphalt will impact measurements. Be sure to take measurements in the same solar/radiant heat environment as the people you are monitoring. Unlike best practices for other measurements, WBGT is intended to be taken in direct sunlight. As long as there is occasional wind the Kestrel has software that allows it to maintain an accurate WBGT reading despite being placed in direct sunlight.

Air Flow

Kestrel Professional Meters can calculate air flow through a duct by combining user input information about the size and shape of the duct with the measured air velocity. In addition to reading the instantaneous Air Flow off the main measurement screen, a more accurate result may be obtained by capturing an average air flow on the Min/Ave/Max screen while traversing the duct. Traversing consists of dividing the area of the duct into evenly sized sections and averaging the air flows at the center of all sections. By spending an equal amount of time at each measurement location and quickly moving between measurement locations, the average air flow measurement can provide a more accurate measure of the air flow in the duct. Capturing an average can be particularly helpful when measuring ducts with registers or dimensionally uneven air flow.

Air Flow Diagram

Evaporation Rate

(Kestrel 5200 Professional Environmental Meter) Kestrel Professional Meters can calculate a concrete evaporation rate (ACI 308) by combining a user input concrete temperature with measured air temperature, wind speed and relative humidity. Concrete mix temperature is generally measured with a probe or infrared thermometer and should be read at the time of making the evaporation rate measurement After inputting the mix temperature, hold the unit vertically, approximately 20 inches above the surface of the concrete while facing the rear of the unit directly into the wind. To avoid inaccurate Evaporation Rate readings due to thermal loading it is best to shade the Kestrel. (Be sure the source of shade is not obstructing the wind speed measurement.) The ACI recommends taking a 6-10 second average of the evaporation rate to account for fluctuating wind speeds. To measure an average Evaporation Rate, scroll right from the Evaporation Current Measurement Screen to the Min/Ave/Max Screen and press select to manually start and stop a capture.

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Yes! The Kestrel 5 Series now has both Android and iPhone integration through our Kestrel LiNK iOS and Android Apps. Kestrel LiNK iOS and Android apps allow LiNK enabled Kestrel 5 Series Meters and DROPs to connect wirelessly with mobile devices to view real-time measurements, receive on-screen alerts, download data and perform firmware updates. The Kestrel LiNK Ballistics app, designed specifically for the Kestrel 5700, Kestrel 5 series Sportsman, and Kestrel 5700 Elite meters, provides full gun management and access to the Applied Ballistics library of G1/G7 curves (5700) and custom drag models (Elite). For a quick look at all of the Kestrel LiNK Application Features - Click Here.

Link Features
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Make sure Bluetooth® is turned ON on your phone. On the Kestrel, go to the Main Menu->Bluetooth and turn it ON. Press the center button while Bluetooth is highlighted and check to ensure that Conct is set to PC/Mobile and it shows Available. Next go to the application that you are connecting with on your phone and select the Kestrel as the device you would like to connect with. Please note: if you do not find the Kestrel on your phone’s “standard” Bluetooth connection screen, that does not mean that the Kestrel is not working properly. Please first go to the application and try to connect through the application. The Kestrel should connect.

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All models of the Kestrel 5000 Series have optical data ports that can be seen through the openings of the battery door. A USB Data Transfer Cable can be purchased separately, which plugs directly into the back of the Kestrel and extends to a USB port in your computer.  You will NOT be able to connect a non-LiNK model unit to a mobile device (e.g., any device without a USB port).

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These programs handle uploading the weather data from the Kestrel to a specific device. This weather data can then be exported into MS Excel. You can also update your firmware any of these programs. Visit the Kestrel LiNK Software and Apps page to learn more.

LiNK Applications Features

LiNK for Desktop LiNK for Mobile Devices LiNK Ballistics for Mobile Devices
LiNK for Windows LiNK for OSX LiNK for iOS LiNK for Android LiNK Ballistics iOS LiNK Ballistics Android
Download stored data log for viewing and saving
Download stored data log for viewing and saving    
Export downloaded data to .csv file for sharing or further analysis
Export downloaded data to .csv file for sharing or further analysis    
  View and analyze downloaded data using range Min/Max/Average statistics and clear scrolling graphs
View and analyze downloaded data using range Min/Max/Average statistics and clear scrolling graphs        
  Set alerts for temperature, heat index, wind, etc.
Set alerts for temperature, heat index, wind, etc.        
  Post snapshots of current conditions to social media with one click
Post snapshots of current conditions to social media with one click        
  Get realtime readings from any Kestrel 5 meter within wireless range
Get realtime readings from any Kestrel 5 meter within wireless range        
  Build and manage gun bullet profiles
Build and manage gun bullet profiles        
  Wirelessly adjust the target range or direction of fire and view elevation and windage solution
Wirelessly adjust the target range or direction of fire and view elevation and windage solution        
  Get comprehensive Applied Ballistics bullet library
Get comprehensive Applied Ballistics bullet library        
  Build and manage gun/bullet profiles
Build and manage gun/bullet profiles        
  Update device firmware
Update device firmware
  Install purchased firmware upgrades
Install purchased firmware upgrades        

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To UPDATE your firmware on any Kestrel you can use the appropriate link below:

As can be seen in the pictures below, place your thumb on the bottom of the unit and slide the latch from the “Locked” to the “Unlocked” position. The battery door should pop up enough that you can remove it. If you have trouble opening the battery door, some slight pressure DOWN on the battery door itself with your other thumb may help release the latch.

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First slide in the tab at towards the top of the unit, then gently press the bottom part of the battery door down until it snaps into place.  Ensure that the O-ring remains in place on the battery door when closing.

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No. Since the Kestrel 5 Series meters utilize only one AA battery, there is no need to use the battery shim to separate two AAA batteries as in the previous version.

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NK strongly recommends continual use of Lithium AA batteries in your Kestrel.  Lithium batteries respond best in extreme temperatures and help prevent against any corrosion.  Customers can also use Alkaline or Nickel Metal Hydride (NiMh) if they prefer, but we recommend turning “Auto Store” to “OFF” when placing these units in storage to minimize the drain on the battery.  Also, please make sure you set the System->Battery setting to match the type of batteries that you are using.

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Overview & Unboxing of the Kestrel Heat Stress Monitoring System

Setting up your Kestrel Heat Stress Monitoring System

Kestrel Heat Stress Monitoring System Overview for Jobsite Heat Safety Monitoring

Connect your Kestrel Heat Stress Monitoring System to Ambient Weather Network for Remote Monitoring

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