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PORTABLE (OPERATOR-CARRIED) SPRAYERS : TEST PROCEDURES

TEST PROCEDURE 1- SURFACE RETENTION TEST

For MK and MB ( engine-driven machines) empty the fuel tank and seal watertight; the fuel fill hole, the carburettor inlet, the exhaust outlet and the outlet of the MB air-tube.

1.1 Stand the sprayer upright on a horizontal wire mesh surface and place a plastic or metal inverted cone with a cone angle of 90° over the lip of the spray tank fill hole. The circumference of the base of the cone should be slightly larger than the fill hole so that liquid poured onto the inverted cone will not enter the spray tank.

1.2 Secure the lance in the "parked" position.

1.3 Take approximately one minute to carefully pour 15 litres of suitable tracer dye solution (i.e. one which is stable and quantifiable to better than 0.01% in solution) centrally and evenly over the cone. The dye solution should flow as evenly as possible over the surface of the spray tank and over the sprayer components attached to it.

1.4 Leave the sprayer standing upright to drain for two minutes then remove the cone.

1.5 Select a tank which is large enough to allow complete immersion of the whole sprayer, without losing any water; e.g. a large plastic barrel or bin. Fill this immersion tank with a known volume of clean water and sample the water to determine any background contamination of the tracer dye chosen for the test.

1.6 Secure the lid tightly to prevent water entering the spray tank, then immerse the sprayer in the immersion tank complete with straps and padding.

1.7 Move the sprayer up and down approximately 25 cm in the water six times and then agitate the water for two minutes.

1.8 Remove the sprayer from the tank; suspend it upright over the tank and allow it to drain for two minutes.

1.9 Vigorously stir the water in the immersion tank for 30 seconds.

1.10 Sample the water and determine by fluorimetry or spectrophotometry the quantity of the original dye solution in the water.

To comply, there must be no more than the equivalent of 10 ml of the original dye solution in the immersion tank, i.e. introduced from the outside of the sprayer.

TEST PROCEDURE 2 - STRAP AND PADDING ABSORPTION TEST

2.1 Remove the straps and padding from the sprayer and record their dry weight.

2.2 Completely immerse the straps and padding in water for two minutes.

2.3 Remove from the water and shake off excess water.

2.4 Drain for one minute in air at 20 -25°C then reweigh.

To comply, the increase in weight should not exceed 5 grams.

TEST PROCEDURE 3 - LEAKAGE TESTS

The three tests in this series should each be carried out independently.

For MK and MB ( engine-driven machines) empty the fuel tank and neatly seal watertight; the fuel fill hole, the carburettor inlet, the exhaust outlet and the outlet of the MB air-tube.

In each case begin by filling the sprayer to its nominal (manufacturer's recommended maximum) capacity with water to which has been added a nonionic surfactant at 0.1% and suitable tracer dye as defined in 1.3 above.

3.1 Non pressurised test (LK,MK,MB)

3.1.1 Wash, clean and dry the complete outside of the sprayer

3.1.2 Place the sprayer with the lance "unparked" on a bench on a clean polythene sheet and leave for 60 minutes.

3.1.3 Immerse the complete sprayer and the polythene sheet in a tank of water and assess any leakage using the procedure specified in clauses 1.5 1.10.

To comply, the test should show a reading equivalent to no more than 5 ml of the original dye solution.

3.2 Pressurised test (LK, MK, CS)

3.2.1 Repeat the procedure in 3.1 but this time, seal the nozzle and pressurise the sprayer to 4 bar with the on/off valve open.

3.2.2 Repeat the test in 3.2.1 with the on/off valve closed.

To comply, in each case, the test should deliver a reading equivalent to no more than 5 ml of the original spray solution.

3.3 Inversion test (all sprayers)

3.3.1 For LK,MK,MB the sprayer should not be pressurised.

3.3.2 For CS the sprayer should be pressurised to 4 bar.

3.3.3 Prepare a tank of water following the same procedure as described in 1.5.

3.3.4 Invert the sprayer and suspend it for five minutes over the tank of water

3.3.5 Follow the procedure in 1.9 to 1.10.

To comply, the test should deliver a reading equivalent to no more than 5 ml of the original dye solution.

TEST PROCEDURE 4 - TANK STRAINER PERFORMANCE TEST

4.1 Using a nonprofiled bucket (i.e. round and without a pouring lip), fill the sprayer to nominal capacity pouring water into the tank through the tank strainer at a rate of:

To comply, the water should pour into the tank without overflowing and in the case of LK, MK and MB, the strainer should not lift from its seating.

TEST PROCEDURE 5 - TRIGGER ON/OFF VALVE RELIABILITY TEST

5.1 Fit the trigger valve, with hose and lance attached, to a suitable mechanical on/off cycling device, so that the valve is operated 1015 times per minute.

5.2 Install a spray nozzle with a discharge rate in the range of 0.7 to 0.8 litres per minute at 3.5 bar.

5.3 Pump water containing a 5% suspension of kaolin( particle size range 0.1 to 4.0 microns) continuously through the spray circuit for the duration of the test at a pressure of 3 bar at the nozzle.

5.4 Operate the valve for 50,000 on/off cycles, at 10-15 cycles per minute.

5.5 Fill the sprayer to its nominal capacity with tracer dye solution as in 1.3, then repeat the procedures in the Leakage Tests 3.1 and 3.2.

To comply:

TEST PROCEDURE 6 - STRAP DURABILITY TEST

6.1 Fill the sprayer tank with water to its nominal capacity.

6.2 Hang the sprayer by its straps from a solid support comprising a horizontal bar of 75 mm outside diameter to simulate its carriage on the shoulder of an operator.

6.3 Lift the sprayer 30 cm and allow it to drop 25 times, always allowing it to hang freely by the straps after each drop.

To comply, the sprayer should continue to function normally after the test and all straps, quick release buckles, connectors and hangers should remain fully serviceable.

TEST PROCEDURE 7 - SPRAYER DURABILITY TEST

For LK, MK, MB

7.1 Fill the sprayer with water to it's nominal capacity.

7.2 For LK fit the pump lever to a mechanical activating device so that the lever does not hit the "stops" at the extreme top and bottom of each stroke.

7.3 For MK and MB, start the engine and operate at the manufacturer's recommended operating speed to comply with the output requirements in 7.4.

7.4 Pump the water from the sprayer at the manufacturer's maximum recommended flow rate and pressure.

7.5 Collect the water from the nozzle(s) in a separate container arranged so that the contents siphon back into the sprayer ensuring that the spray tank does not become completely empty at any time.

7.6 Continue the test :

L K for 250 hours

MK for 100 hours

MB for 100 hours NB Engines are tested for 100 hours.

To comply :

For CS sprayers fitted with manual pumping systems

7.7 In this case do not fill the tank with water.

7.8 Fit the pump plunger to a mechanical activating device to operate so that the plunger does not hit the "stops" at the extreme top and bottom of each stroke.

7.9 Incorporate into the system a pressure valve which at 4 bar allows the pressure in the spray tank to vent completely then re-sets.

7.10 Continue the test for 2,500 venting cycles

To comply:

TEST PROCEDURE 8 - SPRAYER DROP TEST

8.1 Place a solid wooden platform (suggested 50 mm thick by 800 mm square) on a level floor and surround it with a metal cage to protect the examiner from injury.

8.2 Fill the spray tank to its nominal capacity with water.

8.3 For LK, position the lever as near vertically as possible up the side of the tank.

8.4 For LK,MK,CS, park the lance.

8.5 Allow the sprayer to drop, 6 times from a height of 1 metre, onto the platform for each of the following positions :.

i.e. the complete test involves 18 "drops".

To comply, during these tests, no part of the sprayer should break or distort and, following the tests, the sprayer must still be able to function normally and to meet the requirements of the leakage test in Test Procedure 3.

TEST PROCEDURE 9 - CHEMICAL RESISTANCE

This test applies to all components which come into constant direct contact with the concentrated or diluted pesticide formulation. Straps, padding and any seals, which are not in constant direct contact with the chemical, are excluded from this test."

9.1 Weigh and measure the individual components.

9.2 Immerse the components in a solution of 40% v/v kerosene, 20% v/v toluene and 40% v/v xylene for 12 hours at 20-25°C.

9.3 Rinse the components in clean water, dry them and store them for 24 hours in air at 20-25°C.

9.4 Reweigh and remeasure the individual components.

To comply:

TEST PROCEDURE 10 - LIQUID RETENTION IN THE SPRAYER

10.1 Ensure that the sprayer, pump and compression chamber where fitted, hose and lance are nominally empty before commencing the test. i.e. that it is not possible to pump any more liquid from the sprayer.

10.2 Place the sprayer fitted with a nozzle, on a level surface or mounted so that the tank is upright and level. In the case of MB, detach the liquid hose from the air tube.

10.3 Put 5 litres of water in the spray tank.

10.4 Pump the sprayer at a normal operating pressure until no more liquid can be discharged from the nozzle. This step in the procedure will ensure that the amount of spray liquid which is retained in the sprayer in normal practice, should be contained in the sprayer to commence this test.

10.5 Pour a further 5 litres of water containing tracer dye as specified in 1.3. into the tank.

10.6 Pump the sprayer until it is again nominally empty i.e. no more liquid can be discharged and collect all the liquid in a clean container.

10.7 Stir the collected liquid for 30 seconds.

10.8 Sample the liquid and determine the concentration of dye in the water by fluorimetry or spectrophotometry, to measure the dilution.

To comply, the test should deliver a reading which indicates that no more than :

of the original 5 litres of water (10.3) was retained in the sprayer.

TEST PROCEDURE 11 - NOZZLES AND SPRAY QUALITY

11.1 Determination of spray quality

For this test, the spray quality of a candidate nozzle(s) is defined in terms of droplet size distribution compared to the droplet size distribution of the series of conventional flat fan reference nozzles in Table 1.

Table 1

Reference nozzles for defining spray quality categories

nozzle typesflow rates
l/min
pressures
bar
category
boundaries
110 flat fan0.484.5very fine and fine
110 flat fan1.203.0fine and medium
110 flat fan1.962.0medium and coarse
80 flat fan2.922.5coarse and v. coarse

11.2 To evaluate the candidate nozzles

The spray quality of the candidate nozzle(s), is assessed using the same procedure as was

used to calibrate the above reference nozzles to produce Figure 1, as follows:

11.2.1 Spray clean water plus 0.1% nonionic surfactant through the candidate nozzle(s) at the flow rates achieved for the nozzle(s) at 2, 3 and 4 bar.

11.2.2 Determine the droplet size distribution at each of the above flow rates, by sampling the droplets using an appropriate laser beam instrument or other measurement method (e.g. based on capturing surfaces and image analysis).

The sampling protocol should enable the whole of the spray cloud created by the candidate nozzle(s) to be effectively sampled.

Measurements should be made at a distance of between 350 and 500 mm from the nozzle(s).

11.2.3 Plot the results from the candidate nozzle(s) as the cumulative spray volume (xaxis) and the measured drop sizes (yaxis) as shown in Figure 1.

11.2.4 The plots obtained for the candidate nozzle(s) should then be compared to the distribution ranges for the reference nozzles in Figure 1.

To comply, the candidate nozzle(s) drop distribution plot should match the spray quality category claimed for that nozzle(s) by the sprayer manufacturer. A match is achieved where the majority of the cumulative volume, at a given flow /pressure rating, falls in the appropriate category within the range 10-90%.


Figure 2: Spray quality determination based on cumulative volume/droplet size plots

TEST PROCEDURE 12 - SPRAY VOLUME DISTRIBUTION PATTERN

This test is designed to determine the spray distribution across a multi-nozzle boom. It should be carried out with water plus 0.1% nonionic surfactant at a temperature of between 10 and 25°C and a relative humidity above 50%. Actual temperatures and humidity during the test should be recorded and included in the test report.

12.1 Install a single candidate nozzle on a standard patternator bench with 100 mm collecting columns - see Figure 2. The height of the nozzle above the sampling table, should comply with the manufacturer's recommendation on the height of the nozzle above the target.

12.2 Spray the surfactant solution through the nozzle at a constant pressure which should not deviate by more than 2.5% at the nozzle throughout the test.

12.3 Record the distribution of the spray liquid in the patternator when the height of the liquid in the fullest column reaches 90%. Take recordings at 2, 3, and 4 bar.

12.4 By computer analysis, from the levels recorded in the patternator tubes for the single candidate nozzle, calculate the distribution for a 3 metre width (i.e. 30 columns) excluding

the ends where there is no overlap. Calculate the coefficient of variation using the following formula:

where

and xi is the height of liquid in the ith tube.

To comply, the 30 values derived from the patternator columns should show a coefficient of variation of not more than 10% when calculated for the region of overlapping spray.


Figure 3: Diagram of the patternation system

TEST PROCEDURE 13 - ENGINE DURABILITY

Starter mechanism durability

13.1 Fit the engine to a rig to enable the starter mechanism to be subjected to successive test cycles.

13.2 Disconnect the fuel and the engine ignition systems. Warning: Assure adequate lubrication of two stroke engines during the test while the fuel system is disconnected.

13.3 Run the test for 2500 test cycles

To comply, the mechanism should function efficiently during the test period without mechanical breakdown, faults or any need for maintenance.

Engine Durability

13.4 Fill the fuel tank to its nominal capacity.

13.5 Start the engine using the manufacturers recommended starting procedure.

To comply, the engine must start within a maximum of 5 start procedures

13.6 Run the engine at the maximum recommended operating speed until the fuel tank is empty.

13.7 Wait 10 minutes then refill the fuel tank and repeat the procedure until the engine has completed 100 operational hours.

To comply, there must be no breakdown or faults and no maintenance should be required during the test period.

TEST PROCEDURE 14 - MISTBLOWER, HORIZONTAL THROW

This test must be carried out under still air conditions.

14.1 Place watersensitive paper, 10 x 10 cm, on the front face at the top of three 12.5 cm diameter vertical poles, 1.5 metres high, positioned five metres apart in line.

14.2 Walk at a speed of 1 m/sec parallel to and 8.0 metres away from the line of the poles i.e. with the sprayer outlet facing the line of poles.

14.3 Maintain the sprayer outlet at right angles to the line of poles and spray at the manufacturer's minimum recommended flow rate directing the outlet consistently at the level of the water-sensitive papers.

14.4 Repeat the test five times using new target papers each time.

To comply, the mean total number of drops should be no less than 3000 per paper.

TEST PROCEDURE 15 - COMPRESSION SPRAYER, TANK PRESSURE TEST

Pressure limits / tolerance

15.1 Remove the output hose connection, the pressure valves and pressure indicator and securely seal these and any other orifices in the tank with threaded plugs.

15.2 Where the tank is not fitted with a connection for an external pressure source, substitute an appropriate pressure inlet connection for one of the above threaded plugs .

15.3 Completely fill the spray tank with water and place it in a safety cage.

15.4 Couple the tank to a hydraulic pump.

15.5 Pressurise the tank and hold the pressure for one minute as follows:

5 times the nominal pressure (20 bar).

2 times the nominal pressure (8 bar)

To comply, the tank

TEST PROCEDURE 16 - COMPRESSION SPRAYER, PRESSURE CYCLES

This test is designed to test the durability of the complete sprayer and not just the spray tank.

16.1 Where the tank is not fitted with a connection for an external pressure source, fit an appropriate pressure inlet connection.

16.2 Incorporate into the system a pressure valve which at 4 bar allows the pressure in the spray tank to vent completely then re-sets.

16.3 Place the sprayer, with all its normal fittings and complete with hose and lance with the trigger valve closed, filled with water up to nominal filling level, in a safety cage.

16.4 Pressurise the tank to 4 bar for 12,000 pressure cycles

To comply,

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