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CA ARNG Field Quality Assurance Project Plan 9.2 Field Equipment Use and Calibration Numerous instruments and meters will be used in the field during the investigation. The field equipment will be calibrated prior to use, and calibration information will be recorded in a logbook that will remain with each piece of equipment. Measurement equipment that may be needed as various field activities are conducted includes a SC meter, pH meter, temperature meter, turbidity meter, PID, water level indicator, interface sensor, CGI, noise dosimeter, dust monitor, and geophysical instruments. All equipment will be calibrated or checked according to manufacturers' specifications. The results of all calibrations will be recorded in the field logbook. 9.2.1 Specific Conductance Meter The specific conductance meter will be calibrated over the operating ranges expected in the field. Calibration will be made with a potassium chloride standard solution on each day of use. The calibrating standard will not exceed its expiration date. The battery will be checked regularly. The cell cup or electrode will be washed with DI water after each reading, and the cell cup or electrode will be kept clean. 9.2.2 pH Meter The pH meter will be calibrated prior to use for each day that the unit is used. The calibration will include the setting of the range and span with a 7.0 pH buffer and a 4.0 pH or 10.0 pH buffer, depending on whether acidic or alkaline water conditions are expected. The calibrating standards will not exceed their expiration dates. The calibration of the instrument will be checked at the end of each day of use. The pH electrode will contain sufficient liquid, and the outside of the probe will be kept moist. The electrode will be rinsed after each use with DI water and the storage cap replaced. If drifting occurs, the probe will be cleaned and,recalibrated. 9.2.3 Temperature Meter Groundwater temperature will be measured using the temperature compensation probe on the pH meter, the SC meter, or with a mercury thermometer which will be decontaminated after each use. The mercury thermometer will be checked for accuracy with a National Institute for Standards and Technology (NIST) -calibrated mercury thermometer. If the field thermometer does not read within ±2 temperature units, a new field thermometer will be used. 9.2.4 Turbidity Meter The turbidity meter will be calibrated before each well is sampled with a standard supplied by the manufacturer of 0.5 nephelometric turbidity units (NTU). Care will be taken that no air bubbles are in the standard solution and the outside of the vial is clean of all marks affecting the reading, including fingerprints. The turbidity meter requires very little periodic maintenance. The battery will be checked to ensure that it has sufficient charge. Sample vials will be kept clean from smudges and dirt, and the entire instrument will be kept clean and dry. 9.2.5 Photoionization Detector A PID meter with a 10.2 or 10.6 electron -Volt (eV) lamp will be used for measuring non-specific volatile organics in atmospheric concentrations from background levels. At each site, the upwind areas will be selected for a background measurement. Background measurements will be made on a daily basis at each field QAPP.DOC 9-19 May 2000