DAVIS Electronic Rain Counter Manuel d'utilisateur

iChapter 6 Measurement of Precipitation CONTENTS 6.1 Definitions and Units ...

96.3 Maintenance 6.3.1 Sources of Errors Observation errors in measuring precipitation are caused by the influences of the environment, instrume

106.3.2 Maintenance 6.3.2.1 Maintenance before Operation (1) Cylindrical Rain Gauges and Ordinary Rain Gauges a. Check the receptacle for defor

116.3.2.2Periodic Maintenance (1) Cylindrical Rain Gauges a. Inspect the level of the orifice. b. Inspect the cylindrical vessel for dents

12(a) Inspect the receptacle and the funnel and remove dust or leaves. Inspection should be carried out after periods of strong wind. (b) Ins

13 (2) Counters An electromagnetic counter or a recorder to count signals from the tipping bucket rain gauge (3) Miscellaneous a. A stand for the s

14a. Supply water slowly from the receiver funnel. Let the siphon operate once to drain water from the storage tank. Align the pen with the zer

15 Figure 6.16 Example of a siphon rain gauge record

166.5.1 Inspection in Response to Problems 6.5.1.1 Siphon Rain Gauges (1) Procedure for Inspection and Repair in Response to Problems a. P

17 The diameter of the pen support wire must be appropriate for the hole size of the pen adjustment jig. Excessive friction will cause the pen to

18(3) Inspection Procedure a. Check that the connected power source is generating a normal output voltage. Isolate the recorder and ensure that it

1Chapter 6 Measurement of Precipitation 6.1 Definitions and Units Precipitation is defined as liquid or solid condensation of water vapor f

19(c) Adjust the interval at which the pawl ⑦ and detent spring ⑬ engage with the gear to be 70 percent of the notch pitch. (3) Causes of Irr

20conduit from the gauge foundation to the recorder site and connect as required. Plant grass and keep it mowed to prevent raindrops from splashing

21a. Remove the drain cap (⑧, Fig. 6.6) at the bottom of the storage tank and completely drain the water from the tank. Supply fresh water from

226.7 Practical Training Maintenance of rain gauges in operation is described in Section 6.3, Maintenance. This section describes procedures to di

23Note 2: Do not remove the magnet. iv) Remove the reed switch and holder from the base plate. Note: Do not remove the reed switch from the holder

24(c) With most designs, the bearing stone cannot be removed from the base plate of the tipping bucket. After rinsing with water, clean using be

25(2) Verification of Adjustment a. If both buckets tip with 15.7 cm3 of water, fill the measuring glass with water equivalent to 10 mm of precip

26(c) Recording paper is printed or cut improperly Replace the recording paper with a high-quality type. Use paper made by a leading manufactu

27(5) Cautions for Inspection and Adjustment a. Inspection should be carried out using an electric power source and a switch. Adjustment involving

2 A rain-measuring glass may be used instead of a precipitation scale. To measure solid precipitation such as snow and hail with such a device, a

3is also measured with the measuring glass, and is added to the amount of precipitation in the storage bottle. (2) Methods of Observation When pe

4 (2) Methods of Observation The traced mark on the recording paper is read to measure the amount of precipitation. For one-hour pr

5 (1) Structure and Operation This type of rain gauge consists of a receiver and a measuring part, with the receiver serving as the container for

66.2.4 Tipping Bucket Rain Gauge Recorder This recorder counts and records pulses (signals) from a tipping bucket rain gauge, anemometer, etc.

7 The eddy-type cam ⑪ is located on the same shaft as the ratchet gear, and its movement is transmitted to the recorder pen ⑳ through the pen-dr

8Figure 6.11 shows how wind affects precipitation collection. Points A, B and C are located at the top of the receptacle. Assume the wind is blowin