Section 5: Procedures
Before field testing, wash the train glassware, preferably in a dishwasher, with a laboratory glassware detergent. Rinse with acetone, followed by deionized or distilled water. Rinse the sample storage containers with generous amounts of distilled or deionized water.
Pour 15 mL of distilled or deionized water into each of the first two impingers. Leave the last two empty. Assemble the train as shown in Figure 1. Use vacuum grease to seal the joints. "Leak-check" the sampling train at the sampling site at a vacuum of 250 mm mercury. Use the three-way valve to seal the inlet of the impinger train. A leakage rate of not more than one percent of the sampling rate is acceptable.
Position the three-way valve to isolate the impingers from the sampling probe. Place the probe in the stack and adjust the probe heater to the required temperature. Record the barometric pressure, the initial dry gas meter volume, and the inlet and outlet dry gas meter ternperatures. Place crushed ice around the impingers. Purge the probe line using the rubber squeeze bulb.
To start sampling, connect the impingers to the probe line by positioning the three-way valve and immediately turn on the pump. Adjust the sampling rate to approximately 2 L/min. Record the actual initial sample rate. Measure the stack gas velocity by using the procedures described in Method B of Environment Canada Report EPS 1-AP-74-1(1). Determine the ratio of the initial sampling rate to the stack gas velocity. Record this proportionality constant, the instrumentation readings and other pertinent information on the HCl Test Data Sheet (Figure 3). Take readings every five minutes and adjust the sampling rate, if necessary, to maintain the proportionality constant. Add more ice during sampling to keep the temperature of the gases leaving the last impinger at 20°C or less.
At the conclusion of each 20-minute run, turn off the pump and withdraw the probe from the stack. Record the final readings. Conduct a final "leak-check" on the train at a vacuum not exceeding the highest vacuum encountered during the run. A leak rate not above one percent of the sampling rate is acceptable. Disconnect the probe and transport the impinger train to a clean area for sample recovery.
Disassemble the sampling train and pour the impinger contents into a wide-mouth tared sample container. Rinse the impingers, the connectors, and the three-way valve with deionized or distilled water and add the rinsings to the saure container. Determine the weight of the sample solution and record on the HCl Test Data Sheet (Figure 3). Mark the liquid level on the storage container and wrap tape around the cap to prevent sample loss during transit. Label and identify the container. Submit a blank sample of the deionized or distilled water used for each batch of sample.
Evacuate the flexible bag. Assemble the equipment as shown in Figure 2 with the bag disconnected. Place the probe in the stack and purge the sampling line. Connect the bag, ensuring that all connections are tight and leak-free. Sample the stack gas simultaneously with the HCl run. At the end of the test disconnect the bag and analyze the contents for carbon dioxide and oxygen.
Analyze the contents of the bag and repeat the sample analysis until three consecutive analyses vary no more than 0.2% by volume for each analyzed component. The analytical instrument or device should be cross-checked against a commercially available analyzed gas standard. Record the values on the HCl Test Data Sheet (Figure 3).
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