Technical specification
Angle measuring range: +/-20deg
Input power: 18~30Vdc
Consumption lower than 100mA
Waterproof class higher than IP55

Corresponding relations
Angle vs. Voltage: -20deg=1.5V, +20deg=3.5V
Voltage vs. Current: 0~5V vs. 4~20mA
Current vs. Angle as bellows

Angle (deg) current (mA)
-20            8.8
-10            10.4
0              12
10             13.6
20             15.2

Null angle equals 12mA
Sensitivity for each degree vs. Current: 0.16mA
The formula for current converted to angle: Angle = (current-12mA)/0.16mA (unit deg)
The frequency could be up to 20 Hz, according with XW QJ02-003