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Tipping-bucket-rain

1. 00031 Figure 4 Reed switch and heater connections for standard versions 4 2 4 2 1 Heated Versions Standard Single Output Heated Version Release the two catches securing the outer cover to the base and then carefully lift off the cover Feed a suitable length of 2 A 4 core cable through the grommet Connect the instrument ends of two of the cores to the terminals connected to the white leads on the block provided on the underside of the base unit for the output signal Connect the free ends of these cores to the counting device see Figure 4 and Chapter 6 Connect the instrument ends of the other two cores to the terminals on the block connected to the black and red heater leads Connect the free ends of these cores to the power transformer in the hut or enclosure see Figure 4 Go to Section 4 3 Page 8 of 16 Tipping Bucket Rain Gauges Preparation User Manual 4 2 2 Standard Dual Output Heated Version 1 Release the two catches securing the outer cover to the base and then carefully lift off the cover 2 Feed a suitable length of 2 A 6 core cable through the grommet 3 Connect the instrument ends of two of the cores to adjacent terminals connected to the white leads on the block provided on the underside of the base unit for the output signal 4 Connect the free ends of these cores to the first counting device see Figure 4 and Chapter 6 5 Connect the instrument ends of anothe
2. Tipping Bucket Rain Gauges Jan 2006 User Manual Tipping Bucket Heated Tipping Bucket Rain Gauges amp Rain Gauge That Meets The Requirements of The UK Environmental Agency Operator s Handbook HB 3166 06 COPYRIGHT The copyright in this document which contains proprietary information is vested in CASELLA CEL The contents of this document must not be used for purposes other than that for which it has been supplied or reproduced or disclosed wholly or in part without the prior written permission of CASELLA CEL CASELLA CEL CASELLA USA Regent House 17 Old Nashua Road 15 Wolseley Road Amherst Kempston NH 03031 Bedford U S A MK42 7JY U K Toll Free 1 800 366 2966 Phone 44 0 1234 844 100 Fax 1 603 672 8053 Fax 44 0 1234 841 490 e mail info casellausa com E mail info casellameasurement com Web www casellausa com Web www casellagmeasurement com Contents Tipping Bucket Rain Gauges User Manual TABLE OF CONTENTS CONTENTS PAGE I INTRODUCTIONS saina a n RY e a ee ana a LA 3 2 PRINCIPAL OF OPERATION 0 4 3 CONSTRUGHION 324 8248 uE a 4 a AD be ede wees 5 4 PREPARATION FOR USE sis Sa aoaoina a poa aiga aA 6 4 1 Non Heated Versions ooa a a 0 00005 e 6 4 1 1 Standard Single Output Non Heated Version 6 4 1 2 Standard Dual Output Non Heated Version 7 4 1 3 Dual Output Non Heated Version That Meets the Requirements of The UK Environme
3. which should therefore be quoted in any correspondence Casella CEL undertake to rectify any defect in the instrument that is directly attributable to faulty design or assembly and which becomes apparent during the warranty period In order to take advantage of this warranty the instrument must be returned carriage paid to the Casella CEL factory or accredited agent where necessary repairs will be carried out The warranty period runs for 12 months from the date of receipt of goods with exceptions on certain specialised components supplied by other manufacturers which may be warranted for shorter or longer periods by their actual manufacturers In all such cases the benefit of these undertakings will be passed on to the user Casella CEL s liability is limited to items of their own manufacture and they do not accept liability for any loss resulting from the operation or interpretation of the results from this equipment To obtain repair under warranty or for servicing the instrument should be packed and returned in it s original packing or an equivalent to the Service Department at Bedford Insure to full value and ship pre paid For repair or service outside the United Kingdom please return to our appointed distributor Please include a letter giving full details with your packing list It should contain the following information Instrument Type s and Serial Number s Customer name and address Contact name and pho
4. bucket mechanism which relates to 0 2mm per tip X The non heated version to meet the requirements of The UK Environmental Agency has a dual output while dual output versions of the standard rain gauges are available for those users who need independent outputs for example to a counter and to a logger All versions now feature M6 bucket adjusting studs while the version to meet UK Environmental Agency requirements has a larger drop tube diameter 5 mm retained hexagonal headed long base mounting screws to raise the base plate above ground level and quick release terminal blocks with Mil Spec external connectors rated to IP67 When required a heater can be Page 3 of 16 Principle Tipping Bucket Rain Gauges User Manual fitted to the base of this version please consult the Casella CEL sales department 2 PRINCIPLE OF OPERATION The rain gauges comprise a light weight injection moulded plastic divided tipping bucket assembly with stainless steel pivot pins that rest upon stainless steel pins in the support assembly The use of pins produces a rolling rather than pivoting motion when the bucket tips which reduces the likelihood of friction Rain collects in one side of the bucket which tips once a predetermined volume of water has been collected The tipping action discharges the collected water and positions the other side of the bucket under the discharge nozzle ready for filling Each time the bucket is tip
5. rain gauge paying due regard to the following points X No object should be nearer than four times its own height from the bucket X Do not locate the rain gauge in a hollow or on top of a hill X Tall buildings or belts of trees can cause turbulence and gusts which can increase or decrease the rain collected X The surrounding soil should be capable of allowing the discharged water to drain away freely Warning The septum ring has a sharp edge and should be treated with care whenever handling the instrument 4 1 Non Heated Versions 4 1 1 Standard Single Output Non Heated Version 1 Release the two catches securing the outer cover to the base and then carefully lift off the cover 2 Feed a suitable length of 2 A 2 core cable through the grommet 3 Connect the instrument end of this cable to the terminal block provided on the underside of the base unit for the output signal 4 Connect the free end to the counting device see Figure 3 and Chapter 6 Page 6 of 16 Tipping Bucket Rain Gauges Preparation User Manual 5 Go to Section 4 3 4 1 2 Standard Dual Output Non Heated Version 1 Release the two catches securing the outer cover to the base and then carefully lift off the cover 2 Feed a suitable length of 2 A 4 core cable through the grommet 3 Connect the instrument ends of two of the cores to adjacent terminals connected to the white leads on the block provided on the underside of t
6. 1D 0 1 mm Double 103702D 0 2 mm Double 103703D 0 5 mm Double 103704D Versions that 0 2 mm Double 103755D meets the 0 5 mm Double 103759D requirements of The UK Environmental Agency General Notes 1 Purchasers of heated versions must order the TR26 Mains Transformer 220 240 V A C from Casella CEL separately Purchasers of versions that meet the requirements of The UK Environmental Agency may need to obtain a Mil Spec connector Please contact Casella CEL for advice on suitable connectors The manufacturer reserves the right to change these products without notice Casella instrumentation and software is designed manufactured and serviced by Casella CEL Page 15 of 16 Tipping Bucket Rain Gauges User Manual Page 16 of 16
7. ate mounted in its correct location on site adjust the three levelling screws until the built in spirit level indicates that the unit is level Once the unit is level secure the locknuts It is advisable to secure the base unit permanently to a firm foundation using the two holding lugs provided These accept either 9 5 mm or 3 8 rawl bolts Do not over tighten the fixings A restriction such as an elastic band may have been fitted to prevent the bucket from moving during transit Carefully remove any restriction and check that the bucket pivots freely Replace the outer cover of standard versions with the catches engaged in the cutouts in the base plate Replace the outer cover of versions that meet the Environmental Agency Framework Directive then use the Allen Key to lock the three catches to secure the cover to the base The rain gauge is now ready for operation Page 10 of 16 Tipping Bucket Rain Gauges Maintenance User Manual 5 MAINTENANCE Warning The septum ring has a sharp edge and should be treated with care whenever cleaning or handling the instrument Periodically check for debris in the funnel and blockage of the inlet and outlet ports Remove any debris present and clean the meshes The water outlet on the underside of the funnel can be unscrewed allowing the inlet mesh to be removed and cleaned If necessary bucket surfaces can be cleaned using a mild detergent solution Page 11
8. funnel are fabricated from aluminium alloy sheet and again protectively coated Stainless steel mesh is employed to protect the inlet and outlet ports from the ingress of foreign bodies The heater unit on heated rain gauges is operated via an adjustable thermo stat which controls the supply to two power resistors The thermostat is factory set to switch the heater on at 3 C to ensure that the mechanism is kept above freezing point The heater requires a 24 V AC supply which can be obtained from the isolated and fully protected TR26 Mains Transformer available from Casella CEL A cable carries the power to the heater and returns the signal from the tip switch Page 5 of 16 Preparation Tipping Bucket Rain Gauges User Manual 4 PREPARATION FOR USE Each instrument is delivered ready calibrated to indicate either 0 1 mm 0 2 mm or 0 5 mm of rainfall each time the bucket tips The Environmental Agency version is available only with 0 2 mm or 0 5 mm buckets The heated versions require a 24 V AC source which can be obtained from an isolated and fully protected TR26 Mains Transformer that must be ordered separately It is suggested that the transformer be installed in a hut or some other weather proof enclosure that has mains power available It is also recommended that the rain gauge be installed in a location or enclosed compound away from access by the general public Prepare a reasonably level site for the
9. he base unit for the output signals 4 Connect the free ends of these cores to the first counting device see Figure 3 and Chapter 6 5 Connect the instrument ends of the other two cores to the other adjacent terminals connected to the white leads on the block 6 Connect the free ends of these cores to the second counting device see Figure 3 and Chapter 6 Ta Go to Section 4 3 4 1 3 Dual Output Non Heated Version That Meets the Requirements of The UK Environmental Agency This version is delivered with dual outputs pre wired to the Mil Spec external connector in the underside of the base plate Figure 3 The user must supply a suitable cable with Mil Spec connector to couple the outputs from the rain gauge to the two counting devices 1 Connect the plug on the free end of the cable from the Figure 3 Base plate of version that counting device to the con meets the requirements of nector under the base plate The UK Environmental Agency 2 Use an Allen Key to release the three catches securing the outer cover to the base and carefully lift off the cover 3 Go to Section 4 3 Page 7 of 16 Preparation Tipping Bucket Rain Gauges User Manual C Thermostat Terminal 2 1 Heating Elements Bick Block 6R8 6R8 PR Red White White 1 Reed Switch Normally Open White Optional Dual Output Switch Normally Open oe ss White
10. ne number Details of any PC and Software involved including Version Number s Reason for returning the equipment with a detailed description of the fault List of any error messages that may have been displayed The necessary adjustments or repairs will be carried out and the instrument returned as soon as possible Page 13 of 16 Specification Tipping Bucket Rain Gauges User Manual 8 SPECIFICATION 3 1 General Specifications Bucket sizes Aperture Accuracy Capacity Transducer Operating temperature range Output Weight 0 1 mm not version that meets the requirements of UK Env Agency 0 2 mm or 0 5 mm 200 or 400 cm 1 at 1 litre hour Unlimited Magnet Reed switch 1 C to 85 C Contact closure 2 6 kg 8 2 Heated Version Additional Specifications Heater supply voltage Heater power consumption Cable rating Thermostat range Operating temperature range Page 14 of 16 24V AC 42 Watts 2 Aat 24 V AC 4 core 20 C to 40 C 20 C to 85 C Tipping Bucket Rain Gauges Ordering User Manual 9 ORDERING INFORMATION Type Sensitivity Output Catalogue Reference Standard 0 1 mm Single 102471E non heated 0 2 mm Single 100000E 0 5 mm Single 100573E 0 1 mm Double 103700D 0 2 mm Double 103592D 0 5mm Double 103701D Standard heated 0 1 mm Single 103590D 0 2 mm Single 103589D 0 5 mm Single 10359
11. ntal Agency 7 4 2 Heated Versions a ane 6 tiu ge eA i a Ae es 8 4 2 1 Standard Single Output Heated Version aaa 8 4 2 2 Standard Dual Output Heated Version 9 4 2 3 Dual Output Heated Version that Meet the Requirements of The UK Environmental Agency 9 4 3 Generalist na hone hth ate a es i hel en a Ai 10 5 MAINTENANCE wid amp krie a BA oe De er e E a E 11 6 COUNTING BUCKETTIPS mesainin E h Ea 12 6 1 Reed Switch Details 7 SERVICING a a scot Usb chs r a te Blase eit a S 13 8 SPEGIFIGATION gt Rentata oR ESAE Se RRR OS eRe Ree Me ease 14 8 1 Common Specifications 14 8 2 Heated Version Additional Specifications 14 9 ORDERING INFORMATION 00 0 0 cece eee eee 15 Page 2 of 16 Tipping Bucket Rain Gauges Introduction User Manual fl INTRODUCTION Casella Tipping Bucket Rain Gauges are reliable and extremely robust devices that are intended for use as stand alone sensors operating within an existing logging system such as the Casella Automatic or Portable Weather Stations Figure 1 The non heated tipping bucket rain gauge with the outer cover removed Three versions of tipping bucket rain gauge are available X Standard non heated version X Standard heated version for more severe weather conditions X Non heated version constructed to meet the requirements of The UK Environmental Agency X 200cm versions are also available these utilise a 0 1mm
12. of 16 Counting Tipping Bucket Rain Gauges User Manual 6 COUNTING THE BUCKET TIPS A variety of devices may be used to count the bucket tips these include X Data Loggers with contact closure input capability X Event counter a simple LCD counter to indicate bucket tips X Chart Recorder X Computer data acquisition system Consideration should be given to ensure that the counting logging device used can accept a contact closure input For fast counter inputs some form of capacitor resistor filtering may be necessary to reduce bounce effects in the contact signal For details of suitable logging devices please contact the Casella CEL sales department Figure 5 Connections for reed switch 6 1 Reed Switch Details Switching contact closure time is typically less than 100 milliseconds for 0 2 mm of rain N B closure time will be faster for 0 5 mm of rain Maximum current rating 300 mA Breakdown voltage 200 V D C minimum Contact resistance 150 mQ Insulation resistance 10 Q Capacitance open contacts 0 2 pF Life 10 operations Reed switch connections are made via a 2 way terminal block see Figure 5 Page 12 of 16 Tipping Bucket Rain Gauges Servicing User Manual 7 SERVICING To ensure its conformity with the specification this instrument is thoroughly inspected and it s accuracy verified prior to dispatch Test information is filed under the instrument serial number
13. ped a magnet within the bucket moulding closes a reed switch in the support assembly The use of a sealed reed switch capable of indefinite operation ensures the instrument has a long working life Each contact closure pulse represents a discrete amount of rainfall appropriate to the instrument s calibration These tipping pulses may be counted or recorded using a variety of methods as described in Chapter 6 The tipping bucket mechanism is mounted inside the body on a cast aluminium alloy base incorporating a built in spirit level to facilitate correct Tipping Bucket Rain Gauge Accuracy 100 Tips 25 x 7 L Max U K 20 recorded e 15 4 Devon x 0 1mm Tip r O 0 2mm Tip 10 Yy 0 5mm Tip 5 i al 0 0 lt _ 1 Light Moderate Heavy 10 100 1000 Classification WMO 5 Rain fall in mm Hr Figure 2 Accuracy of 0 1 mm 0 2 mm and 0 5 mm tip versions Page 4 of 16 Tipping Bucket Rain Gauges Construction User Manual positioning Both body and funnel are manufactured from aluminium alloy with an accurately machined septum ring with an aperture of 400 cm 200cm version is now also available The measurement accuracy for the various tip sizes is shown in Figure 2 3 CONSTRUCTION The rain gauge is manufactured entirely from non corrosive materials The base and septum ring are cast in Aluminium Alloy LM25 heat treated and protectively coated The outer ring and
14. r two cores to the other adjacent terminals connected to the white leads on the block 6 Connect the free ends of these cores to the second counting device see Figure 4 and Chapter 6 7 Connect the instrument ends of the remaining two cores to the terminals with the black and red heater leads 8 Connect the free ends of these cores to the power transformer in the hut or enclosure see Figure 4 9 Go to Section 4 3 4 2 3 Dual Output Heated Version That Meets the Requirements of The UK Environmental Agency This version is available to special order or the heater unit can be retro fitted to an existing unit please consult the Casella CEL sales department It is delivered with dual outputs and heater pre wired to the Mil Spec external connector in the underside of the base plate see Figure 3 The user must supply a suitable cable with Mil Spec connector to couple the dual outputs on the rain gauge to the two counting devices and the heater to the TR26 24 V power supply ordered separately 1 Connect the plug on the free end of the cable from the counting device to the connector under the base plate 2 Use an Allen Key to release the three catches securing the outer cover to the base and carefully lift off the cover Page 9 of 16 Preparation Tipping Bucket Rain Gauges User Manual 4 3 Go to Section 4 3 General Seal all weather connections using a silicone rubber compound With the base pl

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