STATE OF WASHINGTON DEPARTMENT OF ECOLOGY SOURCE TEST CALIBRATION METHOD V ECOCAL GENERATOR CALIBRATION I. Principle The generator with the Eco cal permeation devices for H 2 S and SO 2 are calibrated over the required ranges with gravimetrically ca librated Teflon permeati on tubes traceable to NBS and Scott-Marrin certified gas standards. Wet chemical methods are used to provide alternate checks. II. Equipment (1) Ecocal Model 202 calibration unit, with H 2 S and/or SO 2 permeation units installed. (2) Barton Analyzer with pump, scrubber, and Teflon tubing. (3) IOC SO 2 Analyzer. (4) Gravimetrically calibrated Teflon permeation tubes and Scott-Marrin certified gases. Constant temperature bath and gas dilution panel. (5) Teflon or Saran bags. Gas tight sy ringes. Calibrated wet test meter. III. Procedure The Ecocal calibration unit is set up with the Barton Titrator a nd IBC Analyzer and connected to the gas dilution panel with tefl on tubing and glass-teflon control valves. The constant temperature bath is allowed to come up to the specified temperature as is the Ecocal unit. Permeation tubes and devices ar e allowed to equilibrate until gas output is steady. (1) For H 2 S: The Barton Titrator is used to determin e the output of the calibrated permeation tubes over the range of 0 – 60 ppm H 2 S. Concentration values of 20, 40, 60 and 80% are sampled through the manifold a nd recorder values are tabulated with allowances for the instrument blanks between each point. Using Teflon or Saran bags of 10 liter capacity, aliquots of H 2 S (99.5%) are injected into the 10 liter measured amounts of scrubbe d air with the gas-tight syringe. After a 15 minute equilibration pe riod and manual mixing in the bag, the bag sample is attached to the Barton Titr ator for measurement. Three samples are introduced at 30, 60 and 90% of the 0 – 60 ppm range. Recorder values are tabulated with allowances for blanks. The Scott-Marrin H 2 S tank value is also recorded after analysis on the Barton Titrator. In order to determine the accuracy an d precision of the set of calibrated permeation tubes, a determination by the zi nc acetate method of the concentration of the 40% value of the permeation tube standard atmosphere will be made. The procedure for the above method is attached as Appendix A.From the above data, a calibration curve is plotted for the Barton Titrator in the range of 0 – 60 ppm H 2 S. The Ecocal calibration unit is then connected to the output manifold of the dilution panel. Using the flowmeter of the Ecocal on the H 2 S channel, five points are recorded on the Barton recorder. Blanks are run between each point and an accurate value is determined for five metered flow rates through the H 2 S permeation device in the Ecocal unit. Using the following formula, a mean permeation rate is determined for the H 2 S permeation device. (Form, Appendix A) ~ P = ppm H 2 S x F .759 Where P = Permeation rate in ng/min. @ 37 degrees C F = Flow rate in cc/min. correct ed for temperature and pressure. A calibration curve is plotted for the Ecocal permeation device for the various settings of the calibrator flowmeter. (2) For SO 2 : The IBC SO 2 analyzer will be used to calibrate the Ecocal SO 2 permeation device in the Tracor calibrator. High-emission Teflon permeation tubes are calibrated gravimetrically and by means of wet chemistry (Appendix C). Four 40 cm high emission SO 2 permeation tubes are stored in a wa ter bath and ventilated container for a period of two weeks, weighed twice weekly on a balance sensitive to 0.1 mg, and calibrated for emission rates by the formula:
P = W 1 -W 2 T Where P = Permeation rate in ng/min.
W 1 = Starting weight in ng.
W 2 = Ending weight in ng. T = Time elapsed in minutes Concentration of SO 2 in a standard atmosphere can be calculated by the formula: ppm SO 2 = .382 x Permeation ra te and tube length Flow rate in cc/min. The IBC SO 2 analyzer is connected to the mani fold of the permeation tube water bath and dilution panel. Air flows are adju sted to give five concentrations of 20, 40, 60 and 100% of the range from 0 to 1000 ppm SO 2 . These points are recorded and care is taken to run duplicates until a linear calibration curve accurate to plus or minus 10 ppm is obtained. A mean perm eation rate is determined for the SO 2 device. The IBC analyzer is now connected to the SO 2 output of the Tracor calibrator. Flows are set on the flowmeter of the ca librator to provide six concentration values over the range of 0 – 1000 ppm. These values are tabulated on the procedure form (Appendix A), and comp ared with the calculated values.Wet chemistry determinations are perfo rmed on the concentration value of approximately 200 ppm SO 2 from the Tracor calibrator. Duplicate runs are made by means of the Hydrogen Peroxide Met hod (Appendix C), and must agree within 10 ppm of the values obtained by calculati on of the permeation tube values above. A calibration curve is plotted of various settings of the calibrator flowmeter. IV. Calculations The procedure form is completed for the two gases and the valu es recorded from the H 2 S and SO 2 analyzers. Two calibration curves are provided for the Tracor calibrator. The curves will show the gas, S/N, and permeation rate of the devices installed in the calibrator, as well as a table of H 2 S and SO 2 ppm values for flowmeter settings of the Tracor calibrator flowmeters.Ecocal Generator – H2S and SO2 Procedure Data Form
H2S Permeation Tube Barton Analyser Std. Atmospheres Blank Recorder

___________ __________

___________ __________

___________ __________

___________ __________ H 2 S Bag Standards Conc.

____________ ___________ __________

____________ ___________ __________

____________ ___________ __________

H 2 S Scott-Marrin Certified Tank Gas No. _________ ___________ __________ Conc. ________________ ___________ __________

Zinc Acetate H2S Method Std. Conc. 1) _____________ Analysis 1) ______________ 2) _____________ 2) ______________

Permeation Rate Tracor Device s/n ________ ______________ ng/minH 2 S Calib. Curve Flowmeter Barton Analyser Reading Flow Rate Calculated Concentration Blank Recorder 1) __________ ___________ ___________________ __________ _________ 2) __________ ___________ ___________________ __________ _________ 3) __________ ___________ ___________________ __________ _________ 4) __________ ___________ ___________________ __________ _________ 5) __________ ___________ ___________________ __________ _________ 6) __________ ___________ ___________________ __________ _________

SO 2 Calib. Curve – IBC Analyser Bath Temp. __________________ Perm. Tub Nos Perm. Rate Flow Rate Calc. Concentration IBC Recorder

_____________ __________ __________ ________________ _______________

_____________ __________ __________ ________________ _______________

_____________ __________ __________ ________________ _______________

_____________ __________ __________ ________________ _______________

SO2 Tracor Device Calibration Cu rve Tracor Calibrator s/n________________ Flowmeter Reading Flow Rate Calculated Concentration IBC Analyser Recorder 1) __________ ___________ ___________________ ___________________ 2) __________ ___________ ___________________ ___________________ 3) __________ ___________ ___________________ ___________________ 4) __________ ___________ ___________________ ___________________ 5) __________ ___________ ___________________ ___________________ 6) __________ ___________ ___________________ ___________________