SKC 303 User Manual

Operating Instructions

863 Valley View Road, Eighty Four, PA 15330 USA

Tel: 724-941-9701 Fax: 724-941-1369 www.skcinc.com

Soap Film Flowmeter

Cat. No. 303

SKC primary standard ﬂ owmeters are designed, manufactured, and tested for accuracy; no calibration is needed. Read the operating instructions thoroughly before operating the ﬂ owmeter.

Principle of Operation

The air sampling pump to be calibrated is connected to and pulls air through the ﬂ owme- ter’s volumetric glass tube where a ﬂ at soap bubble (ﬁ lm) is interposed into the ﬂ ow path. As the airﬂ ow causes the ﬁ lm to move up the volume marks, travel time is measured using a stopwatch. Flow rate can be calculated using the travel time and known tube volume. The 303 Portable Flowmeter Kit is calibrated to a primary standard ± 2% of the volumes marked on the ﬂ owmeter.

Assembly

SKC Model 303 is shipped ready to use. Film solution is supplied as well as a length of rubber tubing to connect the ﬂ owmeter to the pump.

Preparing for Operation

1. Remove the ﬂ owmeter from the case, and place it upright on a level surface.

2. Remove the large rubber stopper from the top of the ﬂ owmeter.

3. Tip the ﬂ owmeter at an angle, and pour a small amount of ﬁ lm solution into the top of the glass tube. The liquid should run down into the rubber bulb at the bo om.

4. Continue adding ﬁ lm solution until it completely ﬁ lls the bulb and rises to just below the side arm inlet. Squeeze the rubber bulb occasionally to release trapped air.

5. Replace the stopper on top of the ﬂ owmeter.

Wetting the Walls of the Tube

The interior walls of the ﬂ owmeter must be wet for the ﬁ lm to travel without rupture. There are two methods:

Method 1

1. Tip the ﬂ owmeter to a horizontal position. Allow the ﬁ lm solution to run out of the rub- ber bulb and into the tube.

2. Maintaining the horizontal position, rotate the ﬂ owmeter so that ﬁ lm solution coats the entire inside surface of the glass. Caution: Do not allow the solution to enter the metal tube in the rubber stopper at the top of the ﬂ owmeter.

3. Return the ﬂ owmeter to an upright position and allow the liquid to ﬂ ow back down into the rubber bulb. Squeeze the bulb occasionally to release trapped air.

Method 2

1. Connect a pump to the ﬂ owmeter (see Connecting a Pump).

2. Turn on the pump. Each successive ﬁ lm that rises up the tube will wet the glass. The walls are suﬃ ciently wet when the ﬁ lm bubbles successfully reach the highest volume mark on the ﬂ owmeter.

Connecting the Pump

Note: If the pump to be calibrated draws air, connect it to the rubber tubing on the ﬂ owmeter’s top rubber stopper. If the pump blows air, use rubber tubing to connect it to the lower side arm near the base of the ﬂ owmeter.

1. Remove the rubber cap from the side arm inlet near the base of the ﬂ owmeter.

2. Using rubber tubing, connect one end to the appropriate port on the ﬂ owmeter and the other end to the inlet of the sampling medium to be used (if applicable).

3. Using ﬂ exible tubing, connect the outlet of the sampling medium to the inlet of the pump.

Sample media outlet

Rubber tubing

Calibration chamber

Sample pump

Inlet

Tygon tubing

Flowmeter

Pump inlet

Outlet (upper port)

Inlet (lower side arm port)

Measuring the Flow

1. Turn on the pump.

2. Squeeze the rubber bulb on the ﬂ owmeter to force the liquid above the inlet. Bubbles (ﬁ lm) will form.

3. Using a stopwatch, start timing the ﬁ lm as it passes the zero line and stop timing as the bubble reaches the 100 ml line. For best results, form several bubbles, ﬁ ve to six seconds apart, and time the last bubble.

Caution: Do not squeeze the bulb continuously. This causes froth to form on the walls making timing diﬃ cult.

The ﬂ ow rate can be determined from the Flow Chart on the back page, or calculated using the following equation:

Flow (ml/min) = 60 x (volume traveled) Time (in seconds)

Storage or Transport

Disconnect the pump and replace the rubber cap on the lower inlet of the ﬂ owmeter. The instrument can be placed in any position without solution loss. SKC recommends that it be transported in its case.

Volumetric Calibration of Hand Pumps

SKC Model 303 Flowmeter can be used to determine the volume of manual hand pumps such as the bellows or piston pumps used with detector tubes. Follow these procedures:

Bellows Pumps (i.e., Dräger®)

1. Connect a detector tube to the pump according to the manufacturer’s instructions.

2. Connect the inlet of the tube to the rubber hose on top of the ﬂ owmeter.

3. Compress the bellows pump and release slowly. Squeeze the rubber bulb on the ﬂ ow- meter. Bubbles (ﬁ lm) will begin to form.

4. When the ﬁ lm reaches the zero line on the ﬂ owmeter, compress the bellows pump com- pletely and release. The ﬁ lm will move up the ﬂ owmeter and stop when the bellows pump is ﬁ lled to capacity.

5. Record the point at which the ﬁ lm stops. Most bellows pumps are designed to draw 100 ml. Lines on the ﬂ owmeter are graduated at 90, 95, 100, 105, and 110 ml. Visually extrapolate the volume reading if the ﬁ lm stops between lines.

6. Calculate and record the volume.

Note: Pumps should be repaired if they fall outside of the 90 to 110 ml range.

Piston Pumps (i.e., Gastec®, MSA, Kitagawa)

1. Connect a standard detector tube to the piston pump according to the manufacturer’s instructions.

2. Connect the inlet of the tube to the rubber hose on top of the ﬁ lm ﬂ owmeter.

3. While pulling the piston slowly back, squeeze the rubber bulb on the ﬂ owmeter until bubbles (ﬁ lm) form.

4. Watch the ﬁ lm movement closely. When the ﬁ lm is exactly at the zero line on the ﬂ ow- meter, push the pump piston all the way in. Then, draw the piston out to full capacity and lock it in place. The ﬁ lm will move up the ﬂ owmeter and stop when the piston pump is ﬁ lled to capacity.

5. Record the point at which the ﬁ lm stops. Most piston pumps are designed to draw 100 ml. Lines on the ﬂ owmeter are graduated at 90, 95, 100, 105, and 110 ml. Visually extrapolate the volume reading if the ﬁ lm stops between lines.

6. Calculate and record the volume.

Note: Pumps should be repaired if they fall outside the 90 to 110 ml range.

SKC Limited Warranty and Return Policy

SKC products are subject to the SKC Limited Warranty and Return Policy, which provides SKC’s sole liability and the buyer’s exclusive remedy. To view the complete SKC Limited Warranty and Return Policy, go to h p://www.skcinc.com/warranty.asp.

Flow Chart for 303 Calibrator

100 ml line 100 ml line 100 ml line ` 100 ml line ` Time Flow Time Flow Time Flow Time Flow (sec) (ml/min) (sec) (ml/min) (sec) (ml/min) (sec) (ml/min)

12 500 44 137 92 65 85 35 13 462 45 133 94 64 87 34 14 429 46 130 96 62 90 33 15 400 47 128 98 61 93 32 16 375 48 125 100 60 96 31 17 353 49 122 102 59 100 30 18 333 50 120 104 58 104 29 19 316 51 118 106 57 108 28 20 300 52 115 108 56 112 27 21 286 53 113 110 55 116 26 22 273 55 111 112 54 120 25 23 261 55 109 114 53 125 24 24 250 56 107 116 52 130 23 25 240 57 105 118 51 135 22 26 231 58 103 120 50 140 21 27 222 59 101 50 ml line 150 20 28 214 60 100 Time Flow 160 19 29 207 62 97 (sec) (ml/min) 170 18 30 200 64 94 60 50 180 17 31 193 66 91 61 49 190 16 32 187 68 88 62 49 200 15 33 182 70 86 63 47 210 14 34 176 72 83 65 46 225 13 35 171 74 81 66 45 250 12 36 167 76 79 68 44 275 11 37 162 78 77 70 43 300 10 38 158 80 75 72 42 330 9 39 154 82 73 74 41 365 8 40 150 84 71 76 39 425 7 41 146 86 70 78 38 500 6 42 143 88 68 81 37 600 5

43 139 90 67 83 36

Accessories and Spare Parts

Description Cat. No.

Film Solution, 1 pint, (473 ml) 302-4011 Precision Digital Stopwatch 303-01-1 Replacement Connecting Hose (2 pieces) P3032101 Replacement Squeeze Bulb P3032311 Replacement Flowmeter Sidearm Cap P3032312

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SKC 303 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual