The first Waterproof, Rugged, Wireless, Environmental Data Logger measuring temperature, humidity and pressure. Monitor and record the conditions of indoor and outdoor environments and easily access real-time as well as historical data on your phone or tablet through a Bluetooth® low energy connection to the Kestrel LiNK app.
Wireless Temperature & Humidity Monitor and Data Logger
$99 Buy Now
The Kestrel DROP D2 is the easiest way to monitor and track temperature, humidity, heat index and dew point in almost any environment – wet or dry, indoors or out.
Wireless Temperature, Humidity, & Pressure Monitor and Data Logger
$129 Buy Now
The Kestrel DROP D3 is designed to monitor and record a full suite of environmental conditions, including temperature, humidity, heat index, dew point temperature, station pressure, density altitude and pressure trend in a variety of indoor, outdoor and industrial applications.
All models available in all three colors: High visibility red, blue and desert tan.
Each DROP logger measures just 1 x 1.8 x 2.4 inches (24 x 46 mm x 60 mm) and weighs just 1.2 ounces (34 grams). DROP loggers meet military and international standards for water, dust and shock resistance (IP-67 and MIL-STD-810G) and are conveniently equipped with a sturdy D-ring for hanging in almost any environment. No wiring or complicated setup, the DROP can also be worn by employees for on-site conditions monitoring.
The Kestrel DROPs employ Bluetooth® low energy technology for wireless data transfer to the Kestrel LiNK App. Bluetooth Smart is the intelligent, power-friendly version of Bluetooth® low energy wireless technology. With Kestrel LiNK you can view real-time readings from any DROP logger within wireless range (100’ or more line of site). You don’t have to actively pull the logger from the field to get the data, you just have to be within Bluetooth® low energy range
Through the Kestrel LiNK app, you can adjust the DROP’s logging interval and set up real-time threshold alerts. Readings can be updated as frequently as every 2 seconds, and logging time and date are automatically updated whenever connected to your smart device. You can also send and share real-time and logged environmental data via email, Facebook or Twitter.
The Kestrel DROPs run on a single coin-cell battery. Adjust the logging interval and other settings, such as real-time threshold alerts and multiple DROP connections to customize connection frequency and battery life to your needs. Store thousands of data points and get months of logging
A Kestrel DROP can hold months of temperature, humidity and pressure data for later retrieval, or you can connect and view conditions real-time (up to 100’ line of sight) with the Kestrel LiNK app. A single phone or tablet can connect to up to 8 DROP loggers concurrently and store data logs from many more. The best part about the Kestrel LiNK app is its ease of use. Once the Kestrel LiNK app is downloaded (free) from the app store, simply turn your phone or tablet’s Bluetooth to “ON,” open the app, connect to your DROP and start logging!
iOS and Android Requirements:
iOS: iOS 6 installed iPhone 4s, iPad 3rd generation or iPod Touch 5th generation – or any later iOS or hardware configuration. Will not work on iPhone 4, 3GS on 3G or any earlier iPad or iPod generation
Android: Android 4.2 and higher. Works with most Android devices with Bluetooth® low energy, including Samsung Galaxy, Nexus 4, Motorola Droid, and other recent generation phones and tablets.
With a wide variety of data loggers on the market, what are the important differences that make the Kestrel DROP the best choice for your application?
"How many times have you been out in the backcountry and wondered, 'How cold did it get last night?' or 'Exactly how hot was that scorching hike?' We wonder that all the time when we're out testing, and now with the Kestrel DROP we finally have the data we want."
"I have been using my D2 to monitor my indoor garden. I started with seeds and I’m hoping to transplant them later this spring. Monitoring the temperature and humidity in the area I have them has led to more sprouts and success than I have had in years past. Humidity has a direct effect on the plant’s ability to transpire at a healthy rate, and being able to take some action around the plants conditions has been awesome."
"We use our D2 to monitor the environment in our car for my canine. He has to be left in our vehicle at times while I visit doctors or have other appointments. We love that we are able to be notified of the environment if the vehicle becomes uncomfortable for him."
"We’ve been using a D2 to monitor the conditions around our goat’s feeding area this spring. The conditions have been all over the place from warm days to snow, so it has been helpful to know the conditions on site for our animals! We’ve used other monitors in the past, but nothing has stood up to the outdoors (and curious goats) like the DROP has."
Kestrel DROP Data Loggers can be easily used in a wide variety of indoor, outdoor and industrial applications. You can employ multiple loggers for pinpoint visibility of where environmental factors are creating unsafe conditions.
Data logging in an academic environment can help teach basic science and environmental principles to children. Leaving a data logger in an indoor or outdoor environment and tracking the temperature, humidity and pressure changes over a period of time can help children explore weather patterns and start to understand how to document and support science experiments with appropriate data and measurements. Learn More »
Temperature monitoring is critical to quality control throughout the food industry. Kestrel DROPs are the ideal tool for accurately tracking and logging temperature to ensure compliance with environmental, health and safety standards, including Hazard Analysis and Critical Control Points (HACCP) regulations. DROPs can be used to monitor temperature along the entire cold chain and food distribution cycle. Learn More »
Kestrel DROPs provide environmental monitoring locally or throughout an entire building with no setup, configuration or wiring required. The units can be used short term for troubleshooting in an isolated area or long term in multiple locations to create a building profile. Data from multiple locations and parameters can be combined for a complete view of building performance. Learn More »
Monitoring agricultural and livestock processes requires a rugged, waterproof device like the Kestrel DROP logger, which is capable of withstanding hot and humid conditions in remote areas. The Kestrel DROP is also the ideal tool for monitoring livestock conditions, during both raising and transportation. Learn More »
Are hot conditions a concern in your workplace? Ensure OSHA compliance and protect employee health and wellness by monitoring conditions with the Kestrel DROP data loggers. View temperature, humidity and heat index exactly where employees are working. Track conditions anywhere needed in a factory, warehouse, farm, storage area or distribution center. Learn More »
For outdoor and indoor use, the Kestrel DROP data loggers help users ensure safe conditions even when they can’t be there. Kestrel DROPs are ideal for monitoring conditions throughout the house, especially in children’s bedrooms, nurseries and basements – anywhere homeowners need peace of mind. Learn More »
Environmental conditions for hunting dogs can be extreme. When temperatures drop to single digits while swimming for ducks or rise to hot double digits during bird season, it’s important to take proper precautions to make sure dogs are properly acclimated. Monitor the exact conditions of hunting dogs by attaching a DROP to a dog’s collar. Learn More »
Rugged, waterproof , drop-proof and dust-proof Kestrel DROP loggers are suitable for almost all manufacturing, process and industrial applications. Kestrel DROPs are small enough to fit in areas other loggers cannot reach, such as pipework, and tough enough to monitor extreme temperatures throughout production processes. Learn More »
Every Kestrel environmental instrument is designed and built entirely in the USA. Kestrel’s history and focus on quality and ruggedness is reflected in the DROP’s industry-leading five-year warranty. Kestrel has been building rugged environmental instruments that help people do their jobs more safely and efficiently for almost 20 years and has built a reputation for reliability, dependability, and accuracy.
Transit Shock Standard
|Measurements||D1 $69||D2 $99||D3 $129|
|Dew Point Temp.||yes||yes|
|Ambient Temperature||+/- 0.9°F / 0.5°C||0.1°F / 0.1°C||14 to 131°F / -10°C to 55°C|
|Relative Humidity||+/- 2% RH||0.1% RH||10% to 90% RH, 25°C non-condensing|
+/ 1.5 hPa|mbar
+/- 3.4°F / 1.9°C
15-95% RH. Refer to range for temp. sensor
|0.1°F / 0.1°C||Temperature, Relative Humidity|
|Heat Index||+/- 7.1°F / 4°C||0.1°F / 0.1°C||Temperature, Relative Humidity|
+/- 69.0 m
+/- 226.0 ft
|Temperature, Relative Humidity, Pressure|
|Operational Range||0°F/-18°C to 140°F/60°C||0 to 100% RH||10-1200 hPa|
|DATA STORAGE||Logged history stored for every measured value. Auto-store interval settable from 2 seconds to 12 hours*, overwrite on or off. D1: >13,000 data points, D2: >7,000 data points, D3: >6,000 data points.|
|SIZE & WEIGHT||2.4 x 1.8 x 0.9 in. / 6 x 4.5 x 2.3 cm. | 1.2oz / 34g (Lithium battery included)|
|BATTERY TYPE||User-replaceable CR2032 (included)|
Bluetooth® Low Energy (BLE) connects to iOS devices
(models 4s and later- see website for complete list of compatible models)
|LOGGING RATE||2 seconds to 12 hours|
|STORAGE TEMPERATURES||-22°F to 140°F / -30°C to 60°C|
|SHOCK RESISTANCE||MIL-STD-810G, Transit Shock, Method 516.5 Procedure IV (4 foot drop test)|
|SEALING||Waterproof (IP67 and NEMA-6)|
|COMPLIANCE||CE certified, RoHS, FCC, IC tested and WEEE compliant. Individually tested to NIST-traceable standards.|
|SOURCE||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.|
We are continuously dedicated to researching ways to improve the Kestrel line and create new products to meet our customers' needs. Learn How
Nielsen-Kellerman Company designs, manufactures and distributes rugged, waterproof environmental and sports performance instruments for active lifestyles and technical applications. Learn More
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