User Manual. 1. Gauge Pneumatic Bubbler Readout. Model 1103/1103hp. User Manual. Man 136. 2.1.0. 06/08/2014. C. Spalton. Andy Small. Chris Rasmussen.
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User Manual 2 Contents Section 1 : Foreword .. .. .. .. . 3 Section 2 : Introduction .. .. .. .. . 4 Section 3 : Equipment Supplied .. .. .. 5 3.01 Equipment .. .. .. .. . 5 3.02 Accessories .. .. .. .. 5 Section 4 : General Description .. .. .. . 6 Section 5 : Performance .. .. .. .. . 7 5.01 Model 1103 .. .. .. .. .. 7 5.02 Model 1103 – HP .. .. .. . 7 Section 6 : Preparing the Readout for Use .. .. .. 8 Section 7 : Charging the Nitrogen Cylinders .. .. .. 9 Section 8 : Taking Readings .. .. .. .. 10 8.01 .. .. .. . 10 8.02 “Flow Mode Method” .. .. .. . 10 8.03 General Note on Taking Readings .. .. . 11 Section 9 : Troubleshooting .. .. .. .. 12 9.01 Leaking i n the Pneumatic Circuit .. .. .. 12 Section 10 : Care and Maintenance .. .. .. 13 Section 11 : Health and Safety Requirements .. .. .. 14 Figure 1: 1103 – 006 Front Panel Layout .. .. .. .. 15 Figure 2: 1103 – 007 – Charging .. .. .. .. 16 Figur e 3: 1103 – 008 Operating Principle .. .. .. . 17 Figure 4: 1103 – 008 Pneumatic Circuit .. .. .. . 18
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User Manual 3 Section 1 : Foreword It is essential that the equipment covered by this manual is both ins talled and operated by competent and suitably qualified personnel. They must READ AND UNDERSTAND the procedures outlined in this manual before attempting installation or operation of the equipment on site. Failure to do this may result in degraded performa nce and reduced reliability. All systems are designed to operate consistently under normal field conditions. The Gauge Pneumatic Bubbler Readout is a precise and sensitive instrument which must be handled with the same care as sensitive surveying instrume nts. Although the components are relatively robust for such sensitivity they will not survive mishandling or neglect. Treat all items with respect and HANDLE WITH CARE. Obviously these techniques can only serve as a general guide and will require modifica tion to suit particular circumstances on site. If difficulties are encountered time will usually be saved by contacting Soil Instruments Ltd at the earliest opportunity. SAFETY NOTE. This readout contains pressure reservoir cylinders which have been teste d and certified in accordance with “Home Office” requirements. The cylinder must be re – tested and certified every five years in accordance with BS 5430 Part 3 or overseas in line with the local regulations. It is also a UK requirement that when a charged r eadout unit is transported on public roads that both the unit and the vehicle carry a non – flammable compressed gas hazard label.
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User Manual 4 Section 2 : Introduction The Bourdon Gauge Pneumatic Bubbler Readout is a portable readout unit for use with all Soil Instruments pneumati c transducers (and other instruments) which operate on the “NO FLOW” or ” principle. A schematic drawing of the basic principle of operation of the pneumatic transducer system is given in Drg. A3/1103 – 008. In this measuring technique the pressure to be monitored is caused to act on one side a sealed flexible rubber diaphragm in the transducer unit which is thus held against the back plate by the applied pressure. Two ports are drilled through the back plate surface and connected to ny lon tubes which extend to the reading point. Referring to Drg. A3/1103 – 008, when a reading is required, gas pressure is applied to the black (send) tube and the magnitude is increased via the pressure regulator until it becomes greater than that of the hyd raulic pressure acting on the other side of the diaphragm. The diaphragm moves away from the pneumatic ports and gas passes into the return tube. As bypass continues in the return tube, gas is detected visually by the air bubbles escaping at a water pot or through a flowmeter. A flow control valve is adjusted to reduce the return line gas flow to a minimum. This stable balance pressure is read directly from the Bourdon Tube Test Gauge on the front panel.
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User Manual 5 Section 3 : Equipment Supplied Pneumatic Readout Model 1103 con sists of the following items. The Pneumatic Bubbler Readout is housed in a strong high impact polypropylene moulded case with a hinged sealed lid and carrying handle. The readout is connected to pneumatic instruments through two quick release couplings an d fly tubes provided as accessories. 3.01 Equipment Gauge Type Pneumatic Bubbler Readout (Model 1103) housed in yellow moulded box. Dimensions : 360 x 280 x 160mm. Weight : 7 Kg. 3.02 Accessories Pair of 2m long nylon flyleads with quick release couplings to co nnect Readout with pneumatic instruments through a terminal panel. Single High Pressure nylon tube with end fittings to connect readout to external industrial Nitrogen cylinder regulator for recharging internal gas cylinder. Pair of safety goggles for us e when re charging internal gas cylinder.
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User Manual 6 Section 4 : General Description The front panel is shown in Drawing No. A3/1103 – 006. All main parts involved in operation and function of the readout are located on the front panel except for the gas bottles and pneumatic tube s. Identification with brief function description is as follows ; A. Pressure Control Valve. It has three positions as marked on the front panel. It connects the send line to regulated gas pressure or exhaust as shown in Drawing No. A3/1103 – 009. B. Flow Contro l Valve. It is a needle valve which controls the gas flow rate into the send line Ref. Drawing 1103 – 009. C. Pressure Regulator. It is located between high pressure gas cylinders and the operational part of pneumatic circuit. Turning it clockwise increases th e regulated i.e. operating, pressure and anticlockwise to reduce or completely shut the gas pressure. D. Regulated Pressure Gauge 0 – 200 psi. Indicates the operating pressure to which the send line and pneumatic sensor will be subjected on switching Valve “A” to apply pressure position. This should always be slightly higher than the expected reading. E. Flow Meter. Floating ball type with flow rate of 20 to 30 ml per minute. F. Cylinder Pressure Gauge. 0 to 1000 psi. This indicates the gas pressure in the internal cylinders. Maximum gas charging pressure of 950 psi may not be exceeded while charging the nitrogen. G. Bourdon Tube 6″ Test Gauge. Depending on the range of pneumatic instruments the gauges can range from zero to 20, 40, 60, 100m Hd or zero to 200 or 350m H d (1103 HP). H. Flowmeter connection to front panel. Quick release fitting for return line. Quick release fitting for send line. “Nitrogen” Nitrogen Gas charging point.
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User Manual 8 Section 6 : Preparing t he R eadout f or Use Before embarking on a visit to site to take a series of readings it is important to ensure that the readout is properly prepared as follows ; 1. Ensure that all items are available i.e. Readout, pneumatic flyleads, cleaning materials for clean ing couplings and notepad/pencil for recording readings. 2. The internal Nitrogen cylinders must be sufficiently charged to ensure enough gas is available for the readings to be taken (refer to Section 7 for charging details). In case of high pressure readin gs greater quantity of gas per reading will be consumed. A careful planning of recharging the gas cylinders is advised to save trips back to base especially over long distances.
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User Manual 9 Section 7 : Charging the Nitrogen Cylinders Refer to Drg. No. A3/1103 – 007 WARNING The r egulator fitted to external nitrogen cylinder controls the charging pressure eliminating any chance of accidentally over pressurising the nitrogen reservoir in the readout. However the operator MUST ALWAYS watch the gauges and never exceed an indicated CYL INDER PRESSURE of 65 bar (950 psi) while adjusting the regulator setting during charging operation. 1. Remove dust cover from bulkhead fitting marked NITROGEN on the front panel. 2. Examine charging flylead and ensure it is undamaged and end fittings are in go od clean condition. 3. Wear Safety Goggles for the following procedures. 4. Ensure Pressure Regulator Valve on the deliver cylinder is closed by turning adjustment knob fully anticlockwise. 5. Connect flylead from readout to regulator on delivery cylinder. Do no t over tighten the brass coupling nuts (it is only necessary to use two fingers on the spanner when tightening the nuts). 6. Using special cylinder key open delivery cylinder valve. 7. Slowly open pressure regulator on delivery cylinder by turning the adjustme nt knob clockwise until flow is heard, accompanied by a rising pressure indicated on the readout CYLINDER PRESSURE GAUGE “F”. 8. Continue to turn the delivery cylinder regulator knob clockwise in stages. Wait until the readout cylinder pressure gauge stabili ses before continuing. 9. When the readout cylinder pressure gauge registers 65 Bar (950 psi) close off delivery cylinder with the key. 10. Close Pressure Regulator Valve by turning adjustment knob on delivery cylinder regulator fully anticlockwise. 11. Carefully remove flylead by slightly loosening brass nut at readout connection marked “NITROGEN”. Allow residue of pressure in flylead to exhaust completely before disconnecting flylead. INFORMATION Always make sure that the flylead is never left connected to the cylinder regulator when not in use. This will prevent “whip – lash” of the flylead in the event of the delivery cylinder valve being accidentally opened. 12. Replace dust cap on “NITROGEN” fitting.
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User Manual 10 Section 8 : Taking Readings All pneumatic instruments of 3P5.2, 3W5.20, 7P 5.1 and 8P2.12 type can be read with this readout using “No Flow” or “Flow Mode” of reading. It is advised that one of the two modes is always used to avoid variance in readings. The two methods are described below. 8.01 Refer to Drg.No. A3/1103 – 006. Connect the Pneumatic Readout to the instrument desired to be read either directly or through the terminal panel. Make sure that quick release couplings are clean and dry. Set Valve “A” to “EXHAUST” position and open Flow Control Valve “B” (tu rn knob anticlockwise 1 to 2 turns). This exhausts the system to atmosphere making the gauge read zero pressure. 1. Close Valve “B” (screw in gently). 2. Set Valve “A” to “OFF” position. 3. Adjust Pressure Regulator “C” to indicate an output pressure on gauge ” D” just in excess of expected reading. 4. Set Valve “A” to APPLIED PRESSURE position. 5. Slowly open FLOW CONTROL Valve “B” (approximately 1/4 turn only) and observe the gauge “G”. The reading should slowly rise. Adjust control Valve “B” as necessary to mainta in steady increase on gauge “G”. After delay (dependent on installed tube lengths) the Flowmeter “E” will indicate gas returning by the float rising in the flowmeter. Adjust flow control Valve “B” to maintain the correct flow, the ball should float between the two indicator lines. 6. Allow flow to continue for approximately 20/30 seconds. 8.1.7 Set Valve “A” to “OFF” position. 7. Reading on the Test Gauge “G” will settle at the balanced pressure and is recorded. 8. Reading may be repeated as a check by resetting V alve “A” to “APPLY PRESSURE” position repeating from Step 2. 9. On completion of readings set Valve “A” to EXHAUST position. Decrease Pressure Regulator “C” to zero pressure (shown on Gauge “D”) and open Flow Control Valve “B”. Set Valve “A” once again to AP PLIED PRESSURE to exhaust the control circuit of residue gas. 10. Finally reset Valve “A” to “OFF” position. 11. Disconnect flyleads and protect fittings with dust caps. 8.02 “Flow Mode Method”
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User Manual 11 This method of reading is less convenient due to time necessary to ac curately maintain a constant low gas flow rate throughout the reading cycle. To obtain the most accurate reading a minimum gas flow must be achieved to “just open” the diaphragm valve in the installed pneumatic transducer. To achieve this requirement the f low rate must be adjusted to maintain the flowmeter ball floating on the lower indicator line in the flow tube. 1. This reading method is identical to the “NO FLOW MODE” method up to step 8.1.6. Further steps are as follows. 2. Refine flow rate adjustment to f loat the ball on lower indicator line. 3. Take the reading on Gauge “G” and record it. This completes the sequence of one reading. Repeat readings or other transducers can be read using same sequence again. 4. After completion of a set of readings, exhaust th e pneumatic lines by turning Valve “A” to “Exhaust” and “B” to open position (2 turns anticlockwise). Disconnect the readout pneumatic flyleads and cover fittings with dust caps. 8.03 General Note o n Taking Readings When carrying out a reading sequence avoid applying excessive flow rate setting by careful adjustment of “FLOW CONTROL Valve B”. Never intentionally allow the flowmeter ball to float to the top of the flow tube; this may give rise to inaccurate readings. Should application of excessive gas flow occ ur it is important to re – set Valve “A” to “OFF” position and allow the flowmeter ball to return to the bottom of the flow tube. A period of several minutes delay should be allowed (depending on tube lengths) before carrying out a new reading sequence. Thi s ensures that any over pressure in the installed instrument tubes dissipates before attempting to carry out further readings.
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