Apogee MU-100 User manual

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Measuring Radiation
Measurements indicate that less than 0.4% of the photon ux
from sunlight falls below 320 nm; 2.3% falls between 320 and
350 nm, and 6% falls between 350 and 400 nm. Although the
UV radiation between 250 and 320 nm is critically important in
photochemical and photobiological reactions, only about 5% of
the UV photons are in this range. Because only a small fraction
of the photons are in the UV-B range, this meter cannot be
used to selectively measure UV-B radiation. The sensor is
sensitive to UV-B radiation, but it is included with the UV-A
radiation to provide a total measurement of UV radiation.
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Using the Meter
1) Press the power button to start. The
meter will turn itself off 2 minutes after
button is pushed to conserve battery.
2) Choose Calibration: To select between
µmol and Watts calibration, push mode once
and up/down to make choice. Once desired
calibration is blinking, press mode three more
times to begin.
3) Choose Mode: To choose between SMPL
and LOG modes push mode twice and up/down
to make choice. Once desired mode is blinking,
press mode two more times to begin.
For Automatic Measurements:
Use LOG mode. Meter will power
on/off to record a measurement every
thirty seconds.
For Manual Measurements: Use SMPL mode.
Press sample to take a measurement. Store up to 99
SMPL measurements.
4) Reset Meter: From LOG or SMPL mode, press mode twice
(RUN should be blinking), then while pressing down, press
mode once.
CAUTION: Resetting will erase ALL measurements.
Ultraviolet Meter
The ultraviolet meter measures and displays instantaneous
readings of the ultraviolet radiation between 250 and 400
nanometers (nm) in micromoles (µmol) per meters per second
or Watts per meters squared.
Ultraviolet Meter
Model MU-100 & 200 Series

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5
(SMPL)
99 Sample
Measurements
(LOG)
99 Log
Measurements
(LOG)
99 Daily Averages
Measurements
Viewable on meter LCD & downloadable Downloadable Only
5) Review Data: Press up/down. To exit and
return to present conditions and the capability
to take measurements, press sample.
6) In LOG mode, every 30 minutes the meter
will average the sixty 30-second measurements
taken and store the average. Ninety-nine
30-minute averaged measurements can be
stored. Every 48 measurements (making a
24-hour period) the meter will also store a
daily total. In addition, 99 daily averages can
be stored and are available for download only.
These measurements are not viewable on the meter LCD. All
measurements taken in LOG mode will continue to be stored
eliminating the oldest measurement.
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Mounting the Sensor
Mount the sensor to a solid
surface with the nylon mounting
screw.
The sensor should be mounted
level for the most accurate
measurements. We recommend
using our leveling plate (AL-
100). The sensor should be
mounted with the cable pointing
toward true north in the northern
hemisphere or true south in the
southern hemisphere to minimize
azimuth error. The azimuth error
is typically less than 1%.
Nylon Screw:
10-32x3/8
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The Clear Sky Calculator was designed to determine the need
for radiation sensor recalibration. It determines the intensity
of radiation falling on a horizontal surface at any time of the
day in any location in the world. It is most accurate when used
near solar noon in the summer months.
The calculator is found at www.clearskycalculator.com and
is used by typing conditions into the Clear Sky model and
comparing measured values with the calculated value for a
clear sky. If the output of the sensor over multiple days at
solar noon is consistently less than the model value (by more
than 8%), the sensor should be cleaned and re-leveled. If
the output is still low after a second test, email calibration@
apogeeinstruments.com to discuss test results and the possible
return of sensors. When used near solar noon over multiple
clear, unpolluted days during the spring and summer months,
it is estimated that the accuracy of the model can be ±4% in
all climates and locations around the world.
Cleaning
Debris on the sensor head is a common cause of low readings.
The sensor has a domed head for improved self-cleaning from
rainfall, but salt deposits can accumulate from evaporation
of sprinkler irrigation water and dust can accumulate during
periods of low rainfall. Salt deposits should be dissolved and
removed with vinegar and a soft cloth or q-tip. Dust and other
organic deposits are best removed with water, rubbing alcohol
or window cleaner. Never use an abrasive cleaner on the lens.

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Example of Model Output
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Characteristics
Level
The meter or sensor must be exactly horizontal for the most
accurate measurement. The most prominent error is caused by
small changes in the position of the sensor.
Cosine Response
The convex disc is designed to capture radiation at low angles
and minimize cosine errors. The cosine error for integrated
daily total measurements is less than 2%.
Temperature Response
Temperature response is less than 0.1% per degree Celsius.
Error Codes
The most common error code is Error 4. The meter will display
this error code on the screen if the battery voltage is too low.
To replace the battery, unscrew the back area on the meter.
Then use a pair of tweezers to gently remove the battery and
replace it with a new one. Screw the back cover back on the
meter, but be careful not to over-tighten as it can affect the
LCD screen.
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Memory
• 99 manually stored data
points
• Automatically store 99
consecutive 30 minute
averages
• 99 daily averages
Range
• 0 - 199.9 µmol m-2 s-1
(full UV in sunlight; 170
µmol m-2 s-1)
Absolute Accuracy
• ± 10%
Input Power
• CR2320 3 V coin cell
battery
Operating Environment
• 0 to 50 C
• Less than 90%
non-condensing, relative
humidity up to 30 C
• Less than 70% relative
humidity from 30 to 50 C
Specications
Display
• 4.2 by 2.8 cm
Long-Term Drift
• Less than 3% per year
Cable (MU-200 Series)
• 2 meters of twisted-pair
wire
• Foil shielded
• Santoprene jacket
• Longer cable lengths are
available in multiples of 5
meters
Dimensions
• 12.6 by 7 by 2.4 cm
Mass
• MU-100: 150 g
• MU-200: 180 g
Warranty
• 1 year against defects in
materials and workmanship
www.apogeeinstruments.com
[email protected]
435.792.4700
Fax: [phone]