Principles of Tipping Bucket:
Tipping bucket rain gauges (TBRs) are frequently used for measuring rainfall rates. The tipping bucket rain gauge consists of
1.Funnel; 2.Tipping bucket; 3.Adjustment screws.
The tiny buckets are manufactured with tight tolerances to ensure that they hold an exact amount of precipitation, typically .01 inch. The tipping bucket assembly is located underneath the rain collector (spout), which funnels the precipitation to the buckets. As rainfall fills the tiny bucket, it becomes overbalanced and tips down; this tipping causes the bucket to empty its content, and the other bucket to position itself below the spout, making it available for filling. The action of each tipping event triggers a small switch that activates the electronic circuitry to transmit the count to the indoor console, recording the event as .01 inch of rainfall. On a wireless rain gage, that count is transmitted via a radio signal. The adjustment screws (3.) determine the volume (Vb) at which a bucket will tip. Higher rainfall rates will result in a higher number of tips per unit of time. From this number of tips the rainfall rate can be determined.
The resolution R of a TBR is the amount of rainfall required for one tip, expressed as a rainfall depth. Since the volume (Vb) is collected over an area A, the resolution can be easily calculated:
R =Vb/A
The procedure to calculate the rainfall rate depends on how the number of tips is registered. One possibility is to register the number of tips n during a fixed time period, the time resolution delta t. In that case, the recorded rainfall rate – or intensity – irec is calculated from:
irec =n · R/delta t
Advantages:
- Tipping bucket measure the rainfall data directly and display the data on interface program software in computer and its make the observer doesn’t need to go to the instruments field.
- The rain character (Light, Medium, or Heavy) can be determined easily.
- Tipping bucket also have unlimited Rainfall capacity.
- Rainfall Output data Tipping bucket can be connected by wireless to connect the interface program in far range.
- This sensor is low cost and very reliable.
Disadvantages:
- The disadvantage of this sensor is need a system that make control of its work and addition components .it’s like power supply, micro controller, and connection module.
- There is the rest of rainfall in bucket which has not fallen and it is make the data have a small deviation if not drained after the last rainfall measurement.
- This instrument underestimates the quantity of rainfall especially during heavy rainfall.
- Susceptible to error due to evaporation, splashing, and high wind.
- For accurate readings, the sensor must be level with no vibration.
- Sensor should be checked regularly to make sure it is not clogged with debris.