# # National Water Information System # 2024/10/03 # # # Date Retrieved: USGS Water Data for the Nation Help System # Code Description 1s 39s A Airline measurement. B Analog or graphic recorder. C Calibrated airline measurement. D Differential Global Positioning System. F Transducer. G Pressure-gage measurement. H Calibrated pressure-gage measurement. L Interpreted from geophysical logs. M Manometer measurement. N Nonrecording gage. O Observed. P Acoustic Pulse measurement. R Reported, method not known. S Steel-tape measurement. T Electric-tape measurement. V Calibrated electric-tape measurement. W Calibrated electric cable. X Uncalibrated electric cable. Z Other.