Surface Rain Gauge Data Collected at Platteville

Data Format



The surface rain gauge data collected at Platteville has the following data format:
Column  Description
1            site ID number
2            year
3            day of year
4            hour & minute of day (without leading zeros)
5            second of minute (10 second increments)
6            Rain Gauge #1
7            Rain Gauge #2
8            Battery voltage
9            Temperature of Campbell electronics

Sample data:
101,2004,159,0,0,0,0,13.84,24.9
101,2004,159,0,10,0,0,13.84,24.9
101,2004,159,0,20,0,0,13.84,24.9
101,2004,159,0,30,0,0,13.84,24.9
101,2004,159,0,40,0,0,13.84,24.9
101,2004,159,0,50,0,0,13.84,24.9

Calibration



The rain gauges were calibrated by pouring 250 ml of water into each rain gauge and counting the number of tips.

For these rain gauges, 16 oz of water should have 100 +/- 3 tips.

16 oz = 454.61 ml.

The ratio of 454.61 ml / 250 ml = 1.818.

Therefore, the number of tips counted with 250 ml of water should be multiplied by 1.818 and should be 100 if perfectly calibrated.

Data collected on 7 June 2004
Rain Gauge #1 (column 6).
Sample  Number of tips
1           50
2           49
3           49
4           52
5           50
6           49
ave      49.8

Adjusting the count by 1.818 : 90.6 tips  The Rain Gauge #1 (column 6) underestimates the rain by 9%

Rain Gauge #2 (column 7).
Sample  Number of tips
1           45
2           44
3           45
4           45
5           43
ave      44.4

Adjusting the count by 1.818 : 80.7 tips  The Rain Gauge #2 (column 7) underestimates the rain by 19%