Kestrel Meter 4000 Portable Anemometer

With at least 17 years of shooting experience behind me, I have personally witnessed how 'full-value' winds (crosswind) affected my shooting accuracy  at ranges beyond 200 meters. As distance increases the drift of the bullet from its original flight path also becomes larger. For example, a 5m/sec wind velocity can deviate your bullet at least 1 meter away from the point of aim (of course, also your intended point of impact) at 500 meters. For this reason, I always study the environment to detect wind velocity (speed and direction). I have read too many literature regarding this matter but I always rely on my own data gathering especially if I am using a hand-loaded ammunition. So, to master the wind estimation techniques (one of the required skill of a sniper), I avail of an excellent tool called the portable wind meter. A very good friend introduced me to his favorite Kestrel wind meter back in 2005. Since then, this device was my constant companion during marksmanship training and competitive shooting matches. 

Aside from wind, shooting accuracy is also affected by other factors such as temperature, humidity and density altitude.  These data are also incorporated into most advanced portable targeting computer applications due to their importance in long range marksmanship. I always required my students to record the temperature during their shooting day to compare the shot group locations when they shoot in a different firing range there is significant change of temperature.

When I was working as a military observer with the United Nations, we were issued the Kestrel 4000 every time we were tasked to assist the landing of small airplanes in an airstrip located in the middle of the swamps.

We reported to the pilots relevant data that he needed such as  wind speed, temperature and humidity in the ground. 

 I like the Kestrel 4000 for its ability to accurately measure all of these parameters in a four-ounce, pocket-size package. 

It is now among the Philippine Army  snipers' 'wish list' of desired gadgets. 

Kestrel 4000

Measurement Response Time	Units	Operational Range	Resolution	Accuracy (+/-)	Specification Range
Wind Speed 1 second	m/s	0.4 to 60.0 m/s	0.1	Larger of 3% of reading or least significant digit	0.4 to 40.0 m/s
	ft/min	59 to 11,948 ft/min	1		59 to 7877 ft/min
	km/h	1.0 to 218.0 km/h	0.1		1.0 to 144.0 km/h
	mph	0.8 to 135.0 mph	1		0.8 to 89.0 mph
	knots	0.6 to 118.3 kt	0.1		0.6 to 78.0 kt
	Beaufort	0 to 12 B	0.1		0 to 12 B
	1 inch diameter impeller with precision axle and sapphire bearings.  Off-axis accuracy -1% @ 5º off-axis; -2% @ 10º; -3% @ 15º.  Calibration drift < 1% after 100 hours use at 16 MPH / 7 m/s.  Sustained operation above 60 MPH / 27 m/s will wear impeller rapidly and may cause destruction of impeller.  Replacement impeller (NK PN-0801) may be field-installed without tools (US Patent 5,783,753).
Temperature 1 second	°F	-49.0 to 257.0 °F	0.1	1.8 °F	-20.0 to 158.0 °F
	°C	-45.0 to 125.0 °C	0.1	1.0 °C	-29.0 to 70.0 °C
	Measures air, water and snow temperature.  Thermally isolated, hermetically sealed, precision thermistor mounted externally (US Patent 5,939,645).  Calibration drift negligible.
Relative Humidity 1 minute	%RH	0.0 to 100.0 %	0.1	3.0 %RH	5.0 to 95.0 % non-condensing
	Polymer capacitive humidity sensor mounted in thin-walled chamber external to case for rapid, accurate response (US Patent 6,257,074).  (To achieve stated relative humidity accuracy, unit must be permitted to equilibrate to external temperature when exposed to large, rapid temperature changes and must be kept out of direct sunlight.)  Calibration drift +/- 2% over 24 months. Relative humidity may be recalibrated at factory or in field using Kestrel Humidity Calibration Kit (NK PN-0802).
Pressure 1 second (mb & PSI 4000 model only)	inHg	0.3 to 32.5 inHg	0.01	0.05 inHg	At 77.0 °F, 22.1 to 32.5 inHg
	hPa / mb	10.0 to 1100.0 hPa / mb	0.1	1.5 hPa / mb	At 25.0 °C, 750 to 1100 hPa / mb
	PSI	0.15 to 16.0 PSI	0.01	0.02 PSI	At 77.0 °F, 10.9 to 16.0 PSI
	Monolithic silicon piezoresistive pressure sensor with second-order temperature correction. Maximum error over temperature range 32 to 158 °F (0 to 70°C) , +/- 0.06 inHg / +/-2.0 hPa. Calibration drift typically -0.03 inHg / -1.0 hPa per year. Pressure sensor may be recalibrated at factory or in field.
Altitude 1 second	ft	-6000 to 30000 ft	1	50 ft	At 77.0 °F, <19,700 ft. Max error +/- 98 ft
	m	-2000 to 9000 m	1	15 m	At 25.0 °C, <6,000 m.  Max error +/- 30 m
	Temperature compensated pressure (barometric) altimeter.
Wind Chill 1 second	°F	0.7 to 135.0 MPH, -49.0 to 257.0 °F	0.1	1.8 °F	1.8 to 89.0 mph, -50.0 to 50.0 °F
	°C	0.4 to 60.0 m/s, -45.0 to 125.0 °C	0.1	1.0 °C	0.4 to 40 m/s, -45.6 to 10.0 °C
	Calculated from the primary measurements of wind speed and temperature.  Utilizes the NWS Wind Chill Temperature (WCT) Index, revised 2001, with wind speed adjusted by a factor of 1.5 to yield equivalent results to wind speed measured at 10 m above ground.  (Specification temperature limits established by WCT Tables.)
Heat Index 1 minute	°F	0.0 to 100.0 %RH, -49.0 to 257.0 °F	0.1	3.6 °F	70.0 to 130.0 °F, 0 to 100% RH
	°C	0.0 to 100.0 %RH, -45.0 to 125.0 °C	0.1	2.0 °C	21.1 to 54.4 °C, 0 to 100 %RH
	Calculated from the primary measurements of temperature and relative humidity.  Utilizes the NWS Heat Index (HI) tables.  (Specification temperature limits established by HI tables.)
Dewpoint 1 minute	°F	0.0 to 100.0 %RH, -49.0 to 257.0 °F	0.1	3.6 °F	-20.0 to 158.0 °F, 20.0 to 95.0% RH
	°C	0.0 to 100.0 %RH, -45.0 to 125.0 °C	0.1	2.0 °C	-29.0 to 70.0 °C, 20.0 to 95.0 %RH
	Calculated from the primary measurements of temperature and relative humidity. Temperature to which the air would need to be cooled at a constant pressure to become saturated.
Wet Bulb Temperature 1 minute	°F	-49.0 to 257.0 °F, 0.0 to 100.0 %RH, 8.86 to 32.48 inHg	0.1	3.6 °F	32.0 to 100.0 °F, 5.0 to 95.0% RH, 8.86 to 32.48 inHg, <19700 ft
	°C	-45.0 to 125.0 °C, 0.0 to 100.0 %RH, 300.0 to 1100.0 hPa	0.1	2.0 °C	0.0 to 37.8 °C, 5.0 to 95.0 %RH, -2000.0 to 9000.0 hPa, <6000 m
	Calculated from the primary measurements of temperature, relative humidity and pressure. Temperature indicated by a wet bulb psychrometer.
Density Altitude  1 second	ft	-49.0 to 257.0 °F, 0.0 to 100.0 % RH, 8.86 to 32.48 inHg	1	246	32.0 to 100.0 °F, 5.0 to 95.0 %RH, 8.86 to 32.48 inHg, <19700 ft
	m	-45.0 to 125.0 °C, 0.0 to 100.0 %RH, 300.0 to 1100.0 hPa	1	75	0.0 - 37.8 °C, 5.0 to 95.0 %RH, -2000 to 9000 hPa, <6000 m
	Calculated from the primary measurements of temperature, relative humidity and pressure.  Air density converted to equivalent sea level elevation at the International Standard Atmosphere.
Max/Avg Wind Speed (Air Velocity), Crosswind, Headwind/Tailwind	One-button clear and restart of Max Wind Gust and Average Wind measurement.
Data Storage / Display	Minimum, maximum, average and logged history stored and displayed for every measured value. 2000-point data logger with graphical display. Auto data storage; interval settable from 2 seconds to 12 hours. Manual data capture.
Data Upload	Requires optional PC interface (NK PN-0830) and provided software. RS-232 connection with USB adapter available.
Display	Multifunction, multi-digit programmable dot-matrix display.
Display Update	1 second.
Display Backlight	Choice of aviation green or visible red electroluminescent backlight. Automatic or manual activation.
Clock / Calendar	Real-time hours:minutes:seconds clock, calendar, automatic leap-year adjustment.
Operational Temperature Range (LCD and Batteries)	The operational temperature range of the liquid crystal display and batteries is 14° F to 131° F / -10 °C to 55 °C. Beyond the limits of the operational temperature range, the unit must be maintained within range and exposed for minimum time necessary to take reading.
Storage Temperature	-22 °F to 140 °F / -30 °C to 60 °C.
Auto Shutdown	User-selectable:  15 or 60 minutes with no key presses or disabled.
Languages	English, French, German, Italian, Spanish.
Certifications	CE certified. Individually tested to NIST-traceable standards (written certificate of tests available at additional charge).
Batteries	AAA Alkaline, two, included. Average life, 400 hours of use, +/-depending on backlight use.
Environmental	Waterproof (IP67 standard). Drop-tested (MIL.STD.810F; unit only. Substantial impact may damage replaceable impeller.).
Dimensions	Unit 5.0 x 1.8 x 1.1 in / 12.7 x 4.5 x 2.8 cm.
Weight	Unit 3.6 oz / 102 g.

	PC Interface for Kestrel 4000 Models With the Kestrel Interface and Communicator Software, data can be uploaded for long-term storage, in-depth analysis and detailed charting. The NEW...
	Replacement Battery Door Replacement Battery Door - Please select the appropriate model. Some of the 4000 Series may require a special order (upto 15 working days - normally...
	Replacement Covers Replace your original lost or damaged cover with this original factory replacement part - available for any Kestrel model/color.
	Spare Impeller (Easy User Install) Replacement impeller for all Kestrel models. Simply presses out, no tools required to change.
	Tripod Large for Kestrel Meters New for Spring 2008! A tripod fitted with the same Kestrel friendly clamp as on our mini tripod. Will accommodate any Kestrel model. Or remove the...
	Tripod Small Clamp any Kestrel into this sturdy but lightweight tripod to take readings in the field. The tripod?s legs extend to permit a maximum height of 10",...
	Vane Mount For All Models The Kestrel Portable Vane Mount is an ingeniously simple accessory designed for extreme light weight and portability. The Vane Mount assembles in...
	Carry Case (Black) This sturdy padded nylon case lets you build a Kestrel 4000 Toolkit perfect for your needs and still carry it on your belt with ease. The top flap...
	Relative Humudity Calibration Kit The RH calibration kit includes the following items: three clear, sealable containers one container with magnesium chloride solution one container...

larger image

larger image