Campbell Scientific 109 109-L Temperature Probe - Page 14

Model 109 Temperature Probe 5: Z=LN(X) (P40) 1: 4 X Loc [ Rs ] 2: 5 Z Loc [ lnRs ] 6: Z=X*F (P37) 1: 5 X Loc [ lnRs ] 2: 0.001 F 3: 6 Z Loc [ Scal_lnRs ] 7: Polynomial (P55) 1: 1 Reps 2: 6 X Loc [ Scal_lnRs ] 3: 7 F(X) Loc [ 1_Tk ] 4: .001129 C0 5: .234108 C1 6: 0 C2 7: 87.7547 C3 8: 0 C4 9: 0 C5 8: Z=1/X (P42) 1: 7 X Loc [ 1_Tk ] 2: 8 Z Loc [ Tk ] 9: Z=X+F (P34) 1: 8 X Loc [ Tk ] 2: -273.15 F 3: 9 Z Loc [ T109_C ] Variations: • Temperature reported as °F - add a multiplier 1.8 using the Z=X*F (P37) instruction, and an offset of 32 using the Z=X+F (P34) instruction. • Ac mains noise filtering - see Section 8.3, Electrically Noisy Environments • Compensate for long cable lengths - see Section 8.4, Long Cable Lengths 7.3 Air Temperature Installation For air temperature measurements, locate probes over an open level area at least 9 m (EPA) in diameter. The surface should be covered by short grass or the natural earth surface where grass does not grow. Probes should be located at a distance of at least four times the height of any nearby obstruction, and at least 30 m (EPA) from large paved areas. Sensors should be protected from thermal radiation, and adequately ventilated. Standard air temperature measurement heights: • 1.25 to 2.0 m (WMO) • 2.0 m (EPA) • 2.0 m and 10.0 m temperature difference (EPA) When exposed to sunlight, the 109 should be housed in a 41303-5A or 413035B six-plate solar radiation shield. The louvered construction of the shields allows air to pass freely through, thereby keeping the probe at or near ambient temperature. The white shields reflect solar radiation. The 41303-5A attaches to a crossarm, mast, or user-supplied pipe with a 2.5 to 5.3 cm (1.0 to 2.1 inch) outer diameter. The 41303-5B attaches to a CM500-series pole or a usersupplied pole with a 5.1 cm (2.4 inch) outer diameter. 8