The 1-character codes listed below are used as part of the element codes for the Soil Moisture and Soil Temperature elements, and indicate the depth at which the sensor is buried.
| Code | Depth (inches) | Code | Depth(inches) | Code | Depth(inches) |
|---|---|---|---|---|---|
| 0 | Unknown | b | 24 | m | 90 |
| 1 | 2 | c | 28 | n | 100 |
| 2 | 4 | d | 30 | o | 110 |
| 3 | 8 | e | 32 | p | 120 |
| 4 | 20 | f | 36 | q | 126 |
| 5 | 40 | g | 42 | r | 192 |
| 6 | 6 | h | 48 | s | 320 |
| 7 | 10 | i | 60 | t | 384 |
| 8 | 12 | j | 64 | u | 448 |
| 9 | 16 | k | 72 | v | 512 |
| a | 18 | l | 80 |