Tempest Sensor Calibrations Follow

All environmental sensors require calibration and that calibration can drift over time. The Tempest System is uniquely designed to facilitate optimal calibration for each user.  It is designed to minimize the level of effort needed to keep Tempest reporting accurately, and toward that end, several calibration steps are automated.  We also provide tools and procedures for maximizing accuracy through manual calibration.  We keep your sensor device optimally calibrated in several ways.

1. Initial Factory Calibration
   All sensors are factory calibrated and arrive at your door, ready to go.
2. Automatic Field Calibration
   Our Continuous Learning process (part of Nearcast Technology) may apply a calibration adjustment to certain parameters based on a sophisticated data analysis process (details vary by parameter).
3. Manual Field Calibration
   Tempest owners can enhance the effectiveness of automatic calibration using manual calibration procedures and tools provided by Tempest. Contact us for calibration adjustments with quantitative, analytical data and provide instrumentation used for comparison measurements. Keep in mind sensors can only be calibrated if outside of accuracy tolerance.
4. Factory Re-calibration
   Once a year, we will perform a factory recalibration for any Tempest owner who requests it. Owner only pays for shipping. Please contact us for details.

Rain

• The factory calibration process for the haptic sensor is not perfect for all rain types and locations. Some devices may need field calibration to fall within the out-of-the box spec.  This field calibration will occur automatically and will bring your Tempest rain gauge within spec. It generally takes three rain events before a calibration is applied and the more rain events, the better it becomes.
• If you have a co-located rain gauge (automated or manual), you can help improve your Tempest’s calibration by providing rain totals from your co-located gauge using this form. 
• Siting and mounting issues can influence the accuracy of any rain gauge. Trees and buildings can block rain. Likewise, a rain gauge located more than 40 inches above the ground will be more influenced by wind. These and other siting issues can lead to larger errors than specified.
• False rain can occur due to mounting or siting issues, when something other than rain is causing vibration detected by the haptic sensor. There are steps that can be taken to eliminate false rain, please see Troubleshooting Measurement & Data: Rain.
• For those devices with chronic false rain where relocating or adjusting the mount is not practical, calibration is not possible. For owners of these devices, we offer a very low-cost Tempest sensor device that can be mounted closer to the ground.

Humidity

• Initial field calibration requires 3-5 days of data
• Local sources of moisture or dryness

Wind

• The wind sensor doesn’t need much calibration because device-to-device differences in the components that affect the wind measurement are very minor.
• Initial field calibration occurs once a few minutes of data from each of the cardinal directions is collected
• Perceived calibration issues are usually due to siting issues. Be conscious of the height above ground and obstacles upwind creating turbulence.
• See Troubleshooting Measurement & Data: Wind for more information

Light/UV

• Initial field calibration requires 3-5 clear days of data

Pressure

• Initial field calibration requires 3-5 days of data

If you need further help with calibration, please contact our support team. We guarantee accurate data or your money back.