2017 WFSTAR: Kestrel Digital Weather Meter Tutorial

Speaker 1:
The purpose of this video is to introduce the novice user to digital weather meters. Since there are various devices on the market,
we will discuss the general abilities, guidelines, and uses of the average weather meter. Weather meters reduce some of the pitfalls
of a Belt Weather Kit, and allow tracking of weather readings and trends. Digital meters perform all of the functions
of the Belt Weather Kit in a single device, though, the process they use is different. Just like the Belt Weather Kit, weather meters
have the ability to measure necessary weather readings, such as wind, temperature, and relative
humidity. Unlike the Belt Weather Kit, most weather
meters use a magnetized impeller to determine wind speed. As the impeller rotates in response to the
wind, it creates a magnetic field, which is sensed by the computer and translated to wind
speed. Most weather meters use thermistors to determine
air temperature. A thermistor is an electronic sensor, whose
resistance changes with temperature. The computer then relates this resistance
to the ambient air temperature. Digital weather meters do not use wet and
dry bulb thermometers to determine RH. Instead, they utilize devices who’s electrical
properties change, based on the amount of water vapor in the air. This eliminates the need for thermometers,
RH tables, and slide rules, and gives a more direct reading of the relative humidity. Weather observations must have accurate readings
in order to be relevant to the needs of the situation. Inaccuracies can compromise fire fighter safety,
and hinder fire line and planning activities. Both tools have sources of air that effect
their accuracy. Digital weather meters generally utilize an
LCD display, that is easy to see and reduces the likelihood of error in reading data. Some meters even feature a back light, which
makes the display visible for use during night operations. All weather meters display realtime data. However, some models allow tracking of weather
trends and can even graph those trends over a desired time span. More advanced meters allow exporting of data
to a PC, or mobile device, using USB, or wireless technology. The size and weight of weather meters is also
a significant advantage over their counterparts, since they can fit in a pocket or holster,
and may only weigh a few ounces. An additional feature that many meters have,
is the ability to measure heat index. This is similar to wind chill. It allows the user to measure the impact of
the heat in a given situation. Weather meters do carry some disadvantages. The wild land Fire environment is unforgiving
for electronics. Heat, dirt, smoke, and water can all have a
negative impact on durability and accuracy. Like most electronics, meters must be handled
with care to avoid damage to the device. Most meters are battery powered, though they
generally use common, lightweight batteries. Some varieties allow for the use of AA batteries,
but any meter is useless is it does not have power to operate. During the fire season, fire equipment is
repeatedly exposed to rough environments that can affect calibration. While calibration drift is typically minimal,
it may eventually decrease the accuracy of readings. To address this issue, most of the manufacturers
offer field calibration kits. The Kestrel is one example of a weather meter
that is commonly used in wild land fire. Most meters work similarly. To use, simply power on the device and face
it into the wind. Be sure to avoid direct sunlight for accurate
readings. Wind speed average and max speed usually display
first. How to scroll through data varies by device. If there is no measurable wind, simply wave
the device from side to side, for up to 15 seconds to get an accurate reading. Be warned, that some models delete stored
data when powered down. When choosing a weather meter, you should
be sure to look for the following features. Wind speed, dry bulb, relative humidity, ability
to show averages and trends. Digital weather meters provide an acceptable
alternative to the traditional Belt Weather Kit. This single device can display all necessary
meteorological measurements, as well as display trends, averages, and historical data. Quality meters eliminate much of the user
error associated with traditional equipment but, they can be fragile. It is also up to the user to be sure they
meet acceptable industry standards. For more information about digital weather
meters, check out these websites. [Sound of a pencil drawing on paper]

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