Tempest Sensor Calibration Follow

A Tempest station includes multiple sensors that, like all environmental sensors, require periodic calibration to correct for slight drift over time. The Tempest System is uniquely designed to minimize the level of effort needed to keep the Tempest device fully calibrated and reporting accurately. Toward that end, all the necessary calibration steps are automated. And while we don't recommend it for most use cases, it’s also possible to apply a manual calibration for users inclined to take this step. Here’s a summary of the processes related to calibration of your Tempest sensors:

1. Initial Factory Calibration
   All sensors are calibrated as part of our manufacturing and testing process, making a Tempest ready to go when it arrives at your door.
2. Automatic Field Calibration
   Our Continuous Learning System (part of Nearcast Technology) may apply a calibration adjustment to certain parameters based on a sophisticated data analysis process (details vary by parameter). This regular, ongoing analysis, which detects and corrects any slight calibration drift, begins as soon as your Tempest is installed and continues for the life of your Tempest.
3. Manual Field Calibration
   Although it’s unnecessary for the vast majority of use cases, if you have a set of quantitative data from a trusted reference source, it’s possible to apply a calibration manually. Contact us for recommendations on the process and instrumentation, and to learn if you might qualify as a product field tester.
4. Factory Re-calibration
   Our production center team will manually recalibrate your Tempest for any owner who requests it, up to once per year. You only pay for shipping. Please contact us for details.

Rain

• Prior to focusing on calibration, please keep in mind that 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 expected based on device specifications.
  The Tempest employs a haptic rain sensor with proven accuracy that has no moving parts and is not affected by problems that affect tipping buckets such as clogging and bearing wear and over-splash. Nonetheless, ”false rain” can be detected when vibration from something other than rain is detected. There are steps that should be taken to eliminate this false rain, please see Troubleshooting Measurements & Data: Rain.
  The haptic rain sensor is particularly sensitive to effects from mounting and device to device variability, making Continuous Learning calibration important. It is also the sensor most likely to benefit from manual field calibration after installation. 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. If you believe your Tempest would benefit from additional calibration, please see Rain Accumulation Calibrations. You may also contact us for support with this process.
  For those devices with chronic false rain where relocating the Tempest or adjusting the mount is not practical, we recommend installing a second sensor closer to the ground. To learn if you qualify for a very low-cost Tempest sensor device for this purpose please contact us. 

Humidity

• Continuous Learning calibration confirmation and adjustment to the humidity sensor may take up to 3 days after installation.
• Keep in mind during installation that one should avoid local sources of moisture or dryness, which can affect readings. These include vents, chimneys, pools of water and vegetation.

Wind

• The wind sensor doesn’t need meaningful calibration because device-to-device differences in the components are very minor and not susceptible to drift.
• The wind sensor does however run an internal balancing routine based on a few minutes of data from each of the cardinal directions in order to ensure ongoing accuracy.
• Note that perceived inaccuracy of wind speed is usually due to issues related to siting, not calibration. Be conscious of the height above ground and obstacles upwind creating turbulence.
• See Troubleshooting Measurements & Data: Wind for more information

Light/UV

• Continuous Learning calibration confirmation and adjustment requires 2-3 hours of clear sky data.

Pressure

• Continuous Learning calibration confirmation and adjustment may take up to 3 days after installation

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