Altitude / Barometric Pressure Calibration of your Kestrel Meter
Start with a known: Either Current Baro Pressure or Current Altitude
NK Recommends identifying their current altitude
Enter this reference altitude on the barometric pressure screen.
For K123s, you would enter this by pressing both outside buttons
Take note of the updated Barometric Pressure that is shown.
Use this updated Baro Pressure as your reference pressure on the altitude screen.
You are now calibrated for your current location / conditions.
Note: If you change altitude, the barometric pressure will become inaccurate.
Note: If a weather system moves in, the altitude will become inaccurate.
What is Sync Alt or Sync Baro?
Both serve the same function (i.e., if you select Yes, both become Yes)
If ON, when you exit the Ref Baro or Ref Alt screen, the Kestrel will input the adjusted Baro (or Alt) into the other screen automatically.
Basically you are saving one step above, but this function only updates once.
This function is only active when in the reference screens.
If OFF, customer has to take note of pressure and manually input in.X
Barometric Pressure – Pressure adjusted to sea level. Need Ref Alt.
Typically only used in meteorology.
Used to equate pressures independent of the altitude in order to view pressure changes / storm fronts.
Station Pressure - Unadjusted pressure. Ref Alt = 0.
This is used in most practical applications outside of weather:
Ballistics, air flight, drag racing, etc.
This is the unadjusted atmospheric pressure felt at that spot.
What do I need to set my reference altitude to if I’m using it for shooting?
For Applied Ballistics and HORUS, the ballistics calculator ALWAYS uses station pressure despite the altitude that is entered.
If users want station pressure, they should set their reference altitude to ZERO.
If you want the altitude to display correctly and have station pressure, you will need the current barometric pressure and enter that as the reference barometric pressure. The reference altitude should remain zero. Sync Alt should be OFF.
I use density altitude for my ballistics program, so what should I set as my reference altitude?
Density altitude is calculated from Temperature, Humidity and Station Pressure. Somewhat counterintuitive, density altitude is not using the altitude number. The Kestrel will always display the correct density altitude no matter what is entered into as the reference altitude.