The TB4, manufactured by Hydrological Services, is a high-end tipping bucket rain gage that has an 8 in. orifice and measures rainfall in 0.01 in. increments. It is ideal for locations where intense rainfall events may occur. This tipping bucket is compatible with all Campbell Scientific dataloggers, and is used in environmental monitoring applications.
The TB4 funnels precipitation into a bucket mechanism that tips when filled to its calibrated level. Each tip is marked by a dual reed switch closure that is recorded by a datalogger pulse count channel. After measurement, the water drains through two orifices (accepts 12 mm tubing) in the base, allowing the measured water to be collected in a separate container.
The TB4 contains an internal siphon mechanism that causes rain to flow at a steady rate to the tipping bucket mechanism (regardless of intensity). The siphon allows the sensor to make accurate measurements over a range of 0 to 50 cm per hour.
The base of the gage is supported by three legs. A CM240 Leveling Base and Mount or a user-supplied baseplate with leveling capability is recommended. The CM240 may be attached to a CM300-series mounting pole, or to a user-supplied 1.5 IPS (1.9-inch outer diameter, unthreaded) pipe (see Ordering Information). A concrete pad is recommended.
Campbell Scientific offers the 260-953 Wind Screen to help minimize the affect of wind on the rain measurements. This wind screen consists of 32 leaves that hang freely and swing as the wind moves past them.
Number of FAQs related to TB4-L: 13
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The CM240 fits the CS700-L, TB4-L, and the retired 385-L rain gages.
The following are some suggestions to try:
Not registering any tips, missing tips, or double tips.
If data is not being logged correctly, there are two likely causes:
The 260-953 Alter-type rain gage wind screen consists of 32 heavy metal leaves that hang freely and swing as the wind moves past them. The swinging leaves act as a wind damper and help minimize the effect of wind on the rain measurements without adding additional turbulence.
Not enough tips or too many tips.
The most common errors are either that the rain gage appears to have drifted out of calibration or that the tips are not being correctly recorded by the datalogger.
When a rain gage is out of calibration, it is usually because of the buildup of dirt and grime on the internal surfaces of the tipping bucket mechanism. Cleaning the internal surfaces usually brings the rain gage back into calibration. It is also possible that a rain gage is out of calibration because it is no longer level.
To minimize the possible occurrence of calibration errors, perform routine cleaning and maintenance of the rain gage at least once every three months. The environmental conditions at a particular site may require a facility to perform cleaning, leveling, and maintenance on a much more frequent schedule.
To incorporate a sensor that is compatible with wireless sensor interfaces into a wireless network, a CWS900-series wireless sensor interface is needed, as well as an A205 CWS-to-PC interface to configure it.