Laserfiche WebLink
1 <br />' GROUNDWATER TECHNOLOGY, INC. <br /> STANDARD OPERATING PROCEDURE <br /> CONCERNING OPERATION/CALIBRATION OF <br />' PHOTOIONIZATION ANALYZER <br /> SOP 19 <br />' 1 The Thermo Environmental Instruments Inc Model 580B OVM Photoionization Analyzer shall be <br /> used, using photoionization, to measure the concentration of trace gases over a range of less than <br />' 1 ppm to 2,000 ppm The specific instrument used for investigations related to hydrocarbon <br /> contamination should be calibrated for direct readings in parts per million (ppm) volume/volume <br /> of isobutylene Specifics of the detection principle/theory and functions of various components can <br /> be found in the manufactures instruction manual <br /> 2 To assure optimum performance,the photolonization analyzer should be calibrated with a standard <br /> gas mixture of known concentration from a pressurized container A daily procedure for calibration <br /> I involves bringing the probe and readout close to the calibration gas, cracking the valve on the tank <br /> and checking the instrument reading This provides a useful spot check for the instrument <br /> 3 A procedure conducted weekly for more accurate calibration of the instrument from a pressurized <br />' container is to connect one side of a 7*to the pressurized container of calibration gas, another side <br /> of the 7" to a rotameter and the third side of the 'T" directly to the 8" extension to the <br /> photoionization probe(see Figure 2) Crack the valve of the pressurized container until a slight flow <br /> Is indicated on the rotameter The instrument draws in the volume of sample required for detection, <br /> and the flow in the rotameter indicates an excess of sample Now adjust the span pot so that the <br /> instrument reads the exact value of the calibration gas (If the Instrument span setting is changed, <br /> the instrument should be turned back to the standby position and the electronic zero should be <br /> readjusted, if necessary) <br /> I <br /> GROUNDWATER <br /> —TECHNOLOGY, INC <br />