What if I don’t have a Campbell data logger?
The sensor takes the measurement and outputs data in RS232 format. If your data logger can receive RS232 signals, it should work with the CS725. It’s also best that the logger can measure volumetric soil moisture.
Are there other things I should measure at the same site as SWE?
Yes, it is best to measure volumetric soil moisture to get a good base-line moisture value just before freeze-up.
What is the purpose of the collimator and is it necessary?
The collimator is a large, steel cylinder that helps reduce gamma from sources other than the ground below the sensor. Non-ground sources include vegetation nearby especially trees.
Are there any site conditions that may hinder the use of the sensor?
The most important aspect of any site is that there is enough naturally occurring 40K. Typically, if there’s vegetation, the site is suitable. To make sure, we recommend a temporary installation with the sensor 3 feet above the ground. Take readings for a minimum of 6 hours and follow the advice in the CS725 Manual (page 25, section 8.3 Obtaining Site Qualifying Counts) for calculating daily 40K values. If you expect SWE will reach 600mm, then you want to see 40K counts of ~96,000 or greater per day, see CS725 Manual (page 27).
Can the sensor output in SDI-12 format?
No, at this time the sensor does not output in SDI-12 format however, it may be added in the future.