Description
The Sky Brightness Tester
(SBT) with Dew Point measures the brightness of the night sky in magnitudes per
square arc seconds, temperature in Celsius and Fahrenheit, relative humidity,
and dew point in Celsius and Fahrenheit.
The resulting information is displayed: 1) on the built-in display, 2) or
can be viewed on the available (free) Android app via Bluetooth (BLE –
Bluetooth Low Energy), 3) or can be viewed on KStars / Ekos Astronomy
Application by using the (free) INDI driver via Bluetooth BLE. The built-in display includes a red covering
to allow user to retain night vision at dark sky areas. The SBT has an oversize switch to allow easy use
with gloves.
* Bluetooth BLE is
employed so that wireless communications can be established in areas that do
not have WiFi / Internet access, such as dark sky areas or other remote
locations.
The SBT is operated by
laying it down on a flat surface with lens pointing straight up at Zenith. For the sky brightness, it reads and averages
16 samples. The display indicates how
many samples have been taken. The latest
16 are averaged together to produce the results. The most stable number is obtained only after
at least 16 samples have been taken. The
system is temperature compensated and adjusts sky brightness readings to the
ambient conditions.
The sky brightness reading
is affected by:
a)
Sun rise and set
* Best readings at least 3 hours after Sun set and 3 hours before Sun rise
b)
The phase of the
Moon (Moon rise and set)
* Best readings at least 3 hours after Moon set and 3 hours before Moon rise
c)
Nearby light
sources
d)
Cloud cover
e)
Humidity, dust or
pollution in air
f)
If dew has formed
on the lens or if the lens is excessively dirty
g)
Location of the
Milky Way, bright stars, etc.
Dew Point & Humidity - The Dew Point indicates how likely it is for dew to form on telescopes and
other equipment. The Dew Point indicates
the temperature at which water vapor will condense into liquid water. Telescopes and other equipment radiate heat
which makes their surfaces colder than the ambient air. Dew will form when the ambient temperature is
near the Dew Point depending on the radiating properties of the material
(metal, glass, etc.). Dew Point and
Humidity readings can be used to determine how successful current astronomy
projects will be. Local Humidity can
vary significantly from humidity readings of nearby weather sources. Including these readings help astronomers
quantitate their local conditions along with Sky Brightness and Temperature. These readings can be used to make decisions
and control telescope configurations to optimize success.
·
Made in the USA
o Designed & built in the USA
o Each unit individually calibrated using an Extech
407026 Heavy Duty Light Meter
·
Light Sensor - AMS
TSL25911: Very High Sensitivity, 600M:1 Dynamic Range, Light-to-Digital
Converter
·
Power: 9V
battery version, 5 to 12V plug-in version (2.1 x 5.5mm jack, center positive)
ð Specify power version when ordering
o Optional 9V Power Supply, or user supplied (clean
power required)
o Estimated 9V battery life: 10 to 15 hours of
operation (temperature dependent)
o 9V current: approx. 30mA, brief period of 60mA at turn
on
o Reverse voltage polarity protection
o No internal lighting during sky sampling period (Going
Dark)
·
OLED display
o Red covered with Rubylith to protect night vision (see
spectrum on website)
o Cycles through multiple displays to provide:
§ Indication of Going Dark for light measuring
§ Sky Brightness & Number of Samples
§ Temperature & Humidity
§ Temperature & Dew Point
·
Weather Accuracy
o Temperature: ± 0.5C
o Humidity: ± 2%
o Temperature & Humidity detector mounted on outside
top to insure accurate reading of ambient conditions
·
Android App
(free)
o Available on Google Play, SBT Sky Brightness Tester
o Download available from www.holland-space.com
o Employees Bluetooth (BLE)
·
INDI Driver
o For use with KStars / Ekos and other INDI compatible
clients
o Available from www.holland-space.com
o Employees Bluetooth (BLE)
·
Field of View: 15.2: (H) x
13.6? (V)
[Oriented with display up]
·
Minimum Sky
Brightness: At least 22 magnitudes per square arc second
·
Overload Indication: An overload condition is indicated when lighting is too bright
·
Temperature
compensated sky brightness readings
·
Size: 12.5 x 6 x
3 cm, 4.9 x 2.4 x 1.2 in
·
Weight: 125g, 5
oz. (with battery)
·
Operating
Temperature: 0 to 70?C
·
Oversized ON/OFF
switch to allow easy operation with gloves
·
Side grips to
decrease chance of accidentally dropping
·
Optional
hard-shell case
o Water proof, impact proof
o Additional room available for other accessories
o If not selected, delivered in reusable cardboard box
·
Optional 9V power
supply for 5 to 12V plug-in version
Items may be returned for a full refund within 60 days as long as they are not physically damaged.