Campbell Scientific SR50-L CSC Ultrasonic Distance Sensor - Manual (Page 22)

SR50 Sonic Ranging Sensor
16
If Flag 2 is high, compute the air temperature compensation factor and correct
the distance-to-surface measurement for air temperature (see Formula 1).
3: If Flag/Port (P91)
1: 12
Do if Flag 2 is High
2: 30 Then Do
4: Z=F (P30)
1: 273.15 F
2: 23
Z Loc [ 273_15 ]
5: Z=X/Y (P38)
1: 22
X Loc [ T_Kelvin ]
2: 23 Y Loc [ 273_15 ]
3: 24 Z Loc [ ATempComp ]
6: Z=SQRT(X) (P39)
1: 24
X Loc [ ATempComp ]
2: 24 Z Loc [ ATempComp ]
7: Z=X*Y (P36)
1: 21
X Loc [ Dis2Surf ]
2: 24 Y Loc [ ATempComp ]
3: 21 Z Loc [ Dis2Surf ]
Add distance-to-ground to distance-to-snow (which is negative) to calculate
snow depth.
In the following instruction, Parameter 2 is a constant. You enter the distance-
to-ground at your site.
8: Z=X+F (P34)
1: 21
X Loc [ Dis2Surf ]
2: 2.0 F
3: 25 Z Loc [ Temporary ]
Move snow Depth to another location so that it can be viewed.
9: Z=X (P31)
1: 25
X Loc [ Temporary ]
2: 10 Z Loc [ SnowDepth ]
10: Do (P86)
1: 22
Set Flag 2 Low
11: End (P95)
Measure the sensor every 15 minutes by setting Flag 1 high.