The Kestrel Handheld Weather Tracker 1) If the unit is configured to log data and it is turned off, will it continue to log temperature data? Wind data? 2) If you turn on the unit and it doesn t take you to the time/date setup automatically, what do you do? 3) How much was the time off when you compared to GMT and what web site did you use to find GMT? 4) How do you average the wind chill measurements over 1 min? 5) How do you make sure that you get a stable humidity reading? What is the situation that can have the most severe effect on the stability of the humidity reading? 6) There are two parameters, that if either of which is known, it will allow the Kestrel to take accurate readings of pressure. What are the two parameters and where can you get them? 7) Use the barometric pressure setting at Lafayette airport to set the reference for the altitude setting. 8) How do you retrieve the station pressure the actual pressure at the site not corrected to sea level? 9) What are the options on the main setup menu? 10) The unit is supposed to measure wind chill. If you navigate through all the observations and you see everything except wind chill, what do you do? 11) List the steps to set the unit to 5 minute data logging. 12) What is the min and maximum sample rate? 13) Can you set it to 15 min sample rate? 14) How many data points can the unit store? 15) What happens when the memory is full?
16) Is it possible to manually store a point at 00:00:07 while the unit is continuously logging data at 10 sec intervals? 17) Will you have more memory to store data and be able to run it longer if you don t log wind chill and heat index? 18) What units can you set the pressure to which would be quite useless for exterior weather measurements? Set the units to metric units. 19) Is it possible to calibrate pressure, temperature, and humidity? 20) What do you do if you can t see the display because of glare? 21) How much time can you log data if you are logging at 2 sec interval? 1 hr interval? 22) How accurate are temperature ( C), wind speed (m/s), RH (%), pressure (mb), dewpoint( C)? altitude (m)? 23) What parameters does the unit actually measure? 24) Will it measure temperature and humidity accurately in the arctic (-50 C)? 25) What is the accuracy of the wind speed at 10m/s? (in m/s) 26) What is the accuracy of the RH sensor at 50% humidity 2 years after the purchase of the unit? 27) Is the barometer more accurate than 1.5 mbar at the top of Mt McKinley? Why? 28) Assuming it was 25C at the top of Mt Whitney, would anyone be able to tell if you were holding the unit while you were sitting down or standing up? 29) While the unit functions within the specified accuracy at -29 C, are there any precautions to take when using it at this temperature? Why? 30) Can it take measurements underwater (please answer without trying)?
Homework 1 The Kestrel Handheld Weather Tracker - Answers 1) 1) If the unit is configured to log data and it is turned off, will it continue to log temperature data? yes Wind data? No (unless autoshutdown is turned off) 2) If you turn on the unit and it doesn t take you to the time/date setup automatically, what do you do Red button, scroll down, date and time, to select. 3) How much was the time off when you compared to GMT and what web site did you use to find GMT? Write the time offset, one website to use is http://wwp.greenwichmeantime.com/ 4) How do you average the wind chill measurements over 1 min? Navigate to wind speed, arrow right > until it says max ---- avg---, to select, wait 1 minute, to select. 5) How do you make sure that you get a stable humidity reading? What is the situation that can have the most severe effect on the stability of the humidity reading? Avoid direct sunlight, hold in airflow of 1 m/s, measure for 2 minutes, verify data graph shows that the value hasn t changed. Severe effects result from a large temperature change right before the measurement and no airflow. 6) There are two parameters, that if either of which is known, it will allow the Kestrel to take accurate readings of pressure. What are the two parameters and where can you get them? Either the precise altitude (ie off a topographic map, not from a handheld GPS) or the barometer from a local airport ( enter KLAF Lafayette airport at http://www.rap.ucar.edu/weather/surface) 7) Use the barometric pressure setting at Lafayette airport to set the reference for the altitude setting.
8) How do you retrieve the station pressure the actual pressure at the site not corrected to sea level? Set the reference altitude to 0 on the Baro screen 9) What are the options on the main setup menu? Off, Memory, Measurements, Graph Scale, Units, User Screens, System, Date&Time, Language, Restore 10) The unit is supposed to measure wind chill. If you navigate through all the observations and you see everything except wind chill, what do you do? Someone must have turned that measurement off, red button main menu, scroll down to Measurements, select, scroll down to wind chill, arrow right > to ON. 11) List the steps to set the unit to 5 minute data logging. Red button main menu, scroll down to Memory, select, scroll down to store rate, arrow right > 5 minutes. 12) What is the min and maximum sample rate? Minimum 2 sec, maximum 12 hrs. 13) Can you set it to 15 min sample rate? No. Only 10 or 20 minutes. 14) How many data points can the unit store? 2000 points. 15) What happens when the memory is full? It starts overwriting the oldest data if overwrite is on, or stops taking data if overwrite is off. 16) Is it possible to manually store a point at 00:00:07 while the unit is continuously logging data at 10 sec intervals?
Yes. After setting up the continuous logging, you can still press the camera button to log a point at that instant. 17) Will you have more memory to store data and be able to run it longer if you don t log wind chill and heat index? Don t know, this has to be tested?? PSI 18) What units can you set the pressure to which would be quite useless for exterior weather measurements? Set the units to metric units. 19) Is it possible to calibrate pressure, temperature, and humidity? Humidity and pressure can be calibrated, with special equipment. 20) What do you do if you can t see the display because of glare? Day/night button. Or Red button main menu, arrow down to System, select, arrow down to Contrast, right arrow to change screen setting. 21) How much time can you log data if you are logging at 2 sec interval? 1 hr interval? 1 hr, 6 min, 40 sec at 2 sec interval, 83 days at 1 hr interval. 22) How accurate are temperature ( C), wind speed (m/s), RH (%), pressure (mb), dewpoint( C)? altitude (m)? 1 C, 3%, 3%, 1.5 mbars, 2 C, 15m. 23) What parameters does the unit actually measure? It measures wind speed, temperature, pressure, relative humidity. The rest are calculated values. 24) Will it measure temperature and humidity accurately in the arctic (-50 C)?
No, it is out of the range where the accuracy is specified. 25) What is the accuracy of the wind speed at 10m/s in m/s? 0.3 m/s. 26) What is the accuracy of the RH sensor at 50% humidity 2 years after the purchase of the unit? 5% which is 3% + 2% possible calibration drift. 27) Is the barometer more accurate than 1.5 mbar at the top of Mt McKinley? Why? The height of Mt. McKinley is 6194 meters which is higher than the range over which the specified accuracy is 1.5 mbar, so it is not guaranteed. 28) Assuming it was 25C at the top of Mt Whitney, would anyone be able to tell if you were holding the unit while you were sitting down or standing up? Mt Whitney is only 4421 m high, so it is the specification range, but the accuracy of the altitude is 15 meters so you can t tell accurately enough how high it is being held above the rocks under your feet. 29) The unit functions within the specified accuracy at -29 C, but are there any precautions to take when using it at this temperature? Why? Take it out only long enough to make the readings and then exposed only for the minimum time, otherwise the LCD display may break. 30) Can it take measurements underwater (please answer without trying)? It is waterproof but it will not make accurate measurements of water temperature. Please avoid getting it wet.