The Comptus A70-‐R Rain Gauge Transmitter is available in a track-‐mounted version when it is to be installed in an existing enclosure. It is also available in polycarbonate, fiberglass steel or stainless steel enclosures.
Each Comptus Rain Gauge or Rain Gauge Transmitter system includes a detailed instruction manual.
Model A70-R Rainfall Transmitter
Accuracy: Electronics: ±1/2% of F.S.
Use: General Monitoring
Model A70 Rainfall Transmitter converts the signal from a tipping bucket rain gauge into a 4-20 mA signal for input to a computer, meters, system controls or other instrumentation. It features reliability, low cost, accuracy, simplicity of operation and ruggedness.
Each tip of the bucket causes the output signal to increase 1% of full scale.
Each complete excursion of the output signal from zero to full scale represents 100 tips of the bucket. This corresponds to one inch or 100 mm of rainfall depending on the calibration of the rain gage. During periods of no rain there is no change in the output signal.
The unit may also be configured for rain detect mode. Contact Comptus for additional information.
The Transmitter is protected from lightning damage with metal oxide varistors.
The A70-RL is available in a track mounted version when it is to be installed in an existing enclosure. It is also available in NEMA 12 steel, NEMA 4X fiberglass and NEMA 4X stainless steel enclosures.
The rain gauge is fabricated of 304 Stainless Steel, PVC and aluminum. It consists of an outer funnel, screen, inner funnel and tipping bucket assembly.
Precipitation entering the collection orifice fills the calibrated tipping bucket assembly. When the bucket fills to the calibrated amount, the bucket tips. Another bucket is brought into place and the precipitation sample is discharged through the dump tubes to the ground below. This produces a switch closure which is detected by the electronics in the Transmitter.
The transmitter electronics count the switch closures from the rain gauge. The counter drives a digital to analog converter which produces a current signal which increases as counts are accumulated. The current signal drives the output amplifier.
|Operating Power:||12-24 VDC|
|Input device:||Tipping Bucket Rain Gauge|
|Output:||Rainfall 4 to 20 mA for 0 - 1 inch|
Electronics: ±1/2% of F.S.
|Temperature Range:||0 to 70° C |
-40 to 70° C available
|Dimensions:||PWB: 6."l X 2.75"w X 1"h|
|Weight:||Transmitter: 1/2 lb. |
2304 Gauge: 10 lbs.
|Maintenance:||Recalibrate system yearly.|
|Connectors:||Terminal strip to accept AWG #12 to #22 Wire|
Model A96 Lightning Arrestor
Additional lightning protection is recommended if any of the cables connected to the instrument are buried or run on top of the ground for a distance of more than 100 feet. The A96 Series of Lightning Protectors are available for this purpose.
The A70-EO is a linear power supply suitable for providing operating power for the system from the AC mains. Two models are available that will provide 10 watts at either 15 or 24 VDC. It will operate from 105 - 130 VAC or 210 - 260 Vac, 50 / 60 Hz.
The A70-LPD is a loop powered display used when displays at multiple locations are required. It is simply installed in series with the 4 -20 mA loop and derives its power from the loop. Each display in the loop introduces a 2.5 volt drop. A 24 Vdc source of excitation is recommended for applications involving the A70-LPD.