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Diffraction Limited Boltwood Portable Cloud Sensor
Diffraction Limited Boltwood Portable Cloud Sensor

Diffraction Limited Boltwood Portable Cloud Sensor

by SBIG
SKU DL-Portable Cloud Sensor
$395.00 USD - $395.00 USD
$395.00 USD
$395.00 USD - $395.00 USD
$395.00 USD
Price Match Policy!
  • Detects cloud cover and daylight
  • Measures sky temperature in the 8 to 14 micron IR band
  • Alerts for "Clear & Dark" or "Cloudy or Light" conditions
  • Over 100 hours of operation on internal batteries
  • Audible beeper and headphone jack for silent alarms
  • Standalone design requires no computer connection
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Diffraction Limited Boltwood Portable Cloud Sensor

    The Diffraction Limited Boltwood Portable Cloud Sensor is a standalone sky monitor that determines cloud cover by measuring infrared radiation in the 8 to 14 micron band. With a battery life of over 100 hours, this portable unit provides audible or silent alerts to keep you informed of changing sky conditions at star parties or any temporary observing site.

    Cloud Detection: An 8 to 14 Micron Infrared Sky Monitor

    The Boltwood Portable Cloud Sensor measures the temperature of the sky by sensing radiation in the 8 to 14 micron infrared band and compares it to the ambient ground-level temperature. A large temperature difference indicates a clear sky, while a small difference signals dense, low-level clouds, allowing the sensor to continuously monitor conditions and alert you to changes.

    Dual Alert Modes: "Clear & Dark" or "Cloudy or Light"

    The control box gives you two distinct alert options depending on your goal. Set it to "Clear & Dark" to sound an alarm when observing conditions become favorable, letting you rest until the sky clears. Alternatively, the "Cloudy or Light" mode will alert you when clouds roll in or dawn approaches, giving you a warning to protect your equipment from the elements.

    Portable Power: Over 100 Hours of Standalone Operation

    Designed specifically for field use, the Portable Cloud Sensor runs for over 100 hours on its internal batteries. The system consists of a sensor head placed outside with an unobstructed view of the sky and a separate control box connected by a cable, which can be kept conveniently inside a tent or building. This completely standalone operation means no computer, Wi-Fi, or external power is required.

    Boltwood Portable vs. Cloud Sensor III: Know the Difference

    This sensor is purpose-built for portability and simplicity, and it's important to understand its limitations. Unlike its permanently installed sibling, the Boltwood Cloud Sensor III, this portable version is not a comprehensive weather station.

    • No Automation: The Portable sensor provides local audible alerts only and has no interface for computer control or automatic observatory dome closure. The Cloud Sensor III is designed for full observatory automation.
    • Limited Sensing: It measures cloud cover and daylight only. It does not measure rain, moisture, wind, or humidity, all of which are monitored by the Cloud Sensor III.
    • Manual Clearing: While a gentle heater prevents dew and frost, the sensor head must be manually wiped dry after a rain shower.

  • How does the Boltwood Portable Cloud Sensor detect clouds?

    It uses an infrared sensor sensitive to the 8 to 14 micron wavelength band to measure the sky's temperature. It compares this reading to the ambient air temperature at ground level. A large temperature difference means the sky is clear, while a small difference indicates cloud cover.

    Can I connect the Boltwood Portable Cloud Sensor to my observatory to close the roof?

    No. The Boltwood Portable Cloud Sensor is a standalone device with no computer or dome connection interface. It provides local audible or headphone alerts only. For automated observatory control, you need the Boltwood Cloud Sensor III.

    What is the difference between the "Clear & Dark" and "Cloudy or Light" modes on the Portable Cloud Sensor?

    These modes determine what condition triggers the alarm:

    • Clear & Dark: The alarm will sound when the sky becomes clear and it is dark. This is useful for waking you up to begin observing.
    • Cloudy or Light: The alarm will sound when clouds appear OR when dawn begins to break. This warns you to stop observing and protect your equipment.

    I'm at a remote star party and want to nap. Can the Boltwood Portable Cloud Sensor wake me if the sky clears?

    Yes, this is a primary use case. Set the control box to the "Clear & Dark" alarm mode. Place the sensor head outside, and the alarm will sound when conditions become suitable for observing, allowing you to rest without missing an opportunity.

    I'm imaging with my portable setup and clouds are threatening. How can the Boltwood Portable Cloud Sensor help?

    Set the alarm mode to "Cloudy or Light". The sensor will sound an alarm when clouds roll in or dawn approaches, giving you an early warning to check your equipment, finish an exposure, or begin packing up before weather becomes a problem.

    What happens if the Boltwood Portable Cloud Sensor gets rained on?

    The sensor does not detect rain. While a small internal heater helps prevent dew and frost, it is not powerful enough to evaporate rainwater. After a rain shower, you must manually wipe the sensor head dry for it to resume accurate cloud detection.

  • Measures Cloud cover (sky vs ambient temperature, 8 to 14 micron IR band) and daylight
    Not Measured Rain/moisture, wind, humidity
    Alerts Audible alarm beeper, headphone jack for silent alarm (headphones not included); alarm on Clear & Dark or Cloudy or Light
    Power Internal batteries, over 100 hours
    Interface / Control None (standalone; no computer or dome connection)
    Sensor Heater Gently heated against dew/frost; must be wiped after rain
    Warranty 1 year

    • Sensor head

      × 1

    • Control box

      × 1

    • Cable

      × 1

  • Diffraction Limited 1-Year Warranty