306WA - Analog trace oxygen analyzer - Teledyne Analytical ...

AppendixModel 306WATo determine the corrected vent flow rate it will be necessary to knowthe ambient temperature (in °K), the ambient pressure (in mm Hg) and thevapor pressure of water at ambient temperature.Ambient temperature can be measured in °Centigrade or °F and convertedto °K.Degrees C = 5 (°F -32)9Degrees K = °C + 273Ambient pressure can be measured with an accurate barometer.or by knowing the altitudeP (mm Hg) = P(in Hg) x 76030.00P(mm-Hg) = 760 - (2.50 per 100 ft. of altitude)*The vapor pressure of water at ambient temperature can be obtainedfrom Table 1 on page A.8.To determine the corrected flow (F corrected), substitute the ambient temperature,pressure and vapor pressure of water in the following formula:F corrected=150 cc/min x T X 760 mm-Hg X (P+Pwater)294 °K** P PWhere:T = ambient temperature (in °K)P = ambient pressure (in mm Hg)P water= vapor pressure of water at ambient temp. (in mm Hg)By way of example, suppose that the target’s position on the flow tubeis in question and it has been determined that the ambient temperature is 77°F and the altitude where the instrument is being used is 5000 ft. above sealevel.Ambient Temp: °K = 5(77–32) + 273 = 298 °K9* This approximation is within ±0.5% of the ICAO Standard Atmosphereover the range 0-7500 ft. above sea level. Ref: “Fluid Mechanics forEngineering Technology” by Irving Granet, Prentice Hall, pp 83–84.**Reference ambient temperature : 294 °K (21 °C) was the ambienttemperature used in the Faradaic calculations.A-6TELEDYNE ELECTRONIC TECHNOLOGIESAnalytical Instruments