Technical Information

Kestrel Weather Australia - Technical information.

User Manuals

Troubleshooting, Repair & Maintenance .

Kestrel Troubleshooting (also see information at the bottom of this page)

Kestrel Impeller Replacement | Download PDF (31 KB)

Kestrel Calibration Kit Instructions | Download PDF (565 KB)

Communicator Computer Software |
PC specific software is available at no cost below:

Kestrel Communicator Interface Software for PC v1.5 (6 mb) Download ZIP file software compatible with ALL Kestrel 4000 series models as at May 2009
Kestrel Communicator Software Instructions Aust | Download PDF (24 KB)

Note: No MAC specific software is available.
You can use an emulation program such as Mac Parallels to run our software.
We are unable to supply emulation software or support for Macs.

USB Adapter Software Drivers Please install first.
XP USB Driver (1.6 MB)
Vista USB Driver (1.7 MB)

Conformity Certificates

Kestrel 1000 Certificate of Conformity
Kestrel 2000 Certificate of Conformity
Kestrel 2500 Certificate of Conformity
Kestrel 3000 Certificate of Conformity
Kestrel 3500 Certificate of Conformity
Kestrel 4000 Certificate of Conformity
Kestrel 4100 Certificate of Conformity
Kestrel 4200 Certificate of Conformity
Kestrel 4500 Certificate of Conformity

Certificate of Conformity - Barometric Pressure
Certificate of Conformity - Relative Humidity
Certificate of Conformity - Temperature
Certificate of Conformity - Wind Speed/Air Velocity

NIST Certificate of Calibration - Barometric Pressure
NIST Certificate of Calibration - Relative Humidity
NIST Certificate of Calibration - Temperature
NIST Certificate of Calibration - Wind Speed/Air Flow

General Maintenance |
Why can’t I close the battery door?
Check the battery door for a possible missing tab or a weak tab on the inside. If the internal tab is missing or weakened, call 610-447-1555 or visit the Kestrel replacement parts page for a replacement battery door.
Why is the unit flashing “E1”?
This means the humidity sensor needs to be recalibrated. If the unit is less than 12 months old (from the date of purchase, send it back to NK for recalibration under warranty. If the unit is more than 12 months old, it can be returned to NK for recalibration for $25 plus shipping, or can be calibrated in the field using the NK Relative Humidity Calibration Kit.

Wind Meter Functions |
How come even with the impeller rotating nothing appears on the display except “0” or “--"?
Turn on the unit and place it near the rear of an electro-magnetic source (i.e. computer, TV, or electric motor). If you get numbers other than “0” or “--", the unit is fine and you just need a new impeller. Call 610-447-1555 or visit the Kestrel® replacement parts page for a replacement impeller. On the other hand, if you still only get “0” or “--", please send the unit in for repair.
Why is the display reading numbers other than “0” even though the impeller is NOT rotating?
The unit is probably picking up electro-magnetic fields from elsewhere (i.e. nearby computer, TV, or electric motor). Simply remove the electro-magnetic source.
Why is the impeller of my Kestrel® Windmeter NOT balanced? Why does one blade remain down no matter how I rotate the rest of the instrument?
The Kestrel impeller IS balanced, and to a very high degree. It APPEARS to be imbalanced because of the tiny magnet incased within the impeller. The force acting on your impeller blade is magnetic, not gravitational. If you want to test this out, simply hold your Kestrel horizontally, and then rotate the entire instrument in the horizontal plane. PIC You will see that the impeller does not rotate. It acts like a compass and remains stationary. This is how it SHOULD act when properly operating.

Looking at the issue more technically, there are no known effects from either the weak or strong forces. The earth’s magnetic field has a vertical component everywhere but the equator, and this component creates a torque on the magnet mounted on the impeller shaft. Although the earth’s field does provide a weak aligning force, which causes the impeller to oscillate as it comes to a stop, there is NO effect on the accuracy of the windspeed reading. This is because the force acting on the impeller is “conservative” – it has no effect on the rotation speed. The conservative force causes acceleration of the impeller in equal and opposite measure to the deceleration every time the impeller completes an entire rotation.

Rest Assure that any new impeller from NK has been calibrated and tested to be well within the specified accuracy of plus/minus 3% (our recent test have been much closer to ±2%). The impeller needs NO ADJUSTMENT. If your Kestrel® application involves hours of intense high-speed use, you may want to consider purchasing a replacement impeller ($19.00) once a year to ensure that your Kestrel maintains factory specified accuracy.

Temperature Functions |
Why does my temperature reading seem inaccurate?
To take an immediate measurement, you must keep the air moving around the temperature sensor. 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) until the case temperature equalizes with the air temperature. When equalized, the display will read a constant value. Be aware that this could take as long as twenty minutes.

Humidity Functions |
Why does my humidity reading seem inaccurate?
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.

The humidity sensor has been factory calibrated to be accurate to within ±3%. If your Kestrel appears to no longer meet this specification, it may need to be recalibrated. NK now offers a Relative Humidity Calibration Kit for your home use.

Technical Information

User Manuals

Troubleshooting, Repair & Maintenance .

Communicator Computer Software | PC specific software is available at no cost below:

Conformity Certificates

Communicator Computer Software |
PC specific software is available at no cost below: