One of the reasons that the WatchDog 2000-series weather stations are so widely used is that they are designed so that they do not require as much maintenance as other stations. All sensors are pre-calibrated at the time of manufacturing, and most do not require subsequent calibrations. The sensors have been chosen so that the weather station can immediately be placed into operation, and the stations are designed so that they can be left unattended for months at a time if necessary. The station design is modular, which allows the user to cost-effectively replace any component that fails.
A recertification service is available; contact your dealer or Spectrum for details. This is primarily intended for stations that are over 5-7 years old, and is most cost-effective for domestic customers who wish to send their stations for Spectrum for overall checking, firmware updates, and repair/replacement of parts as needed.
Specifically, the maintenance that we recommend is as follows:
- Batteries: For full-size weather stations (models 2900ET, 2700, 2550), alkaline batteries need to be replaced approximately every 10 months, or every 12 months if using lithium batteries. For mini stations (24xx models), alkaline batteries need to be replaced every 12 months. This does not apply for customers who are using a DataScout modem, Mid-Range Wireless (with solar panel), the powered direct-connect cable, or where the optional solar panel and rechargeable batteries have been installed.
- Rain Collector: this should be checked every several months if possible, to ensure that debris has not accumulated in the rain bucket (e.g, leaves, bird droppings, etc.). The end-user should also periodically remove the rain bucket from the base in order to clear any debris that might have accumulated under or around the tipping buckets themselves, for example insect nests. If the customer feels that rain measurements are becoming less accurate, they may re-calibrate the tipping buckets according to the instructions we provide in the product manual, or in the rain calibration article in the knowlege base.
- Temperature and Relative Humidity (Full-Size Stations prior to 2016 or Mini Stations): The RH sensor may need to be replaced over time if it begins to drift; this primarily happens in dirty or dusty environments, or environments that are exposed to chemical sprays, high levels of marine salt, etc. We recommend RH sensor replacement every 4-5 years, as this is a low-cost sensor that can easily be user-replaced as part of general long-term maintenance (item 3612RHS). (Many customers use their weather stations for longer periods of time, and do not experience any problems with RH drift.) The air temperature sensor is not user-replaceable; rather, it consists of a thermistor that is permanently soldered onto the T/RH board. The sensor does not typically fall out of calibration, but if it ever fails, then the T/RH module on the station must be be replaced.
- Temperature and Relative Humidity (2016 or later Full-Size Stations ): Temperature and RH are measured by a single sensor, which can be replaced if the RH value begins to drift. This primarily happens in dirty or dusty environments, or environments that are exposed to chemical sprays, high levels of marine salt, etc. We recommend Temp/RH sensor replacement every five years, as this is a low-cost sensor that can easily be user-replaced as part of general long-term maintenance (item 3613WD). However, many customers use their weather stations for longer periods of time, and do not experience any problems with RH drift.
- Light Sensors: Light sensors (PAR, solar radiation) can be recalibrated, but this requires that they be returned to Spectrum to use a NIST-certified light source. The sensors will stay in close calibration for many years (8-10) with very minimal drift.
- Wind speed and direction: Wind speed calibration cannot be done without using a wind tunnel, but periodic onsite inspection and a spinning of the wind cups to confirm that the cups spin freely with minimal resistance should be sufficient to provide confidence in the values reported on the station. One can also visit the station site with a portable Wind/T/RH device in order to validate that readings are similar between the devices. The anemometer assembly is modular in design; it can be replaced if necessary, and at lower cost than sending the sensor for testing and recalibration. Wind direction can be validated by using a compass and pointing the wind vane in a known direction to confirm that the reading is accurate. This step is performed at the time of installation, but occasionally stations are moved by the user and care may not be taken to redefine wind direction on the station.