40 CFR §63.9921

1. (a)For each wet scrubber subject to the operating limits in § 63.9890(b) for pressure drop and scrubber water flow rate, you must install, operate, and maintain each CPMS according to the requirements in paragraphs (a)(1) and (2) of this section.
   1. (1)For the pressure drop CPMS, you must:
      1. (i)Locate the pressure sensor(s) in or as close to a position that provides a representative measurement of the pressure and that minimizes or eliminates pulsating pressure, vibration, and internal and external corrosion.
      2. (ii)Use a gauge with a minimum measurement sensitivity of 0.5 inch of water or a transducer with a minimum measurement sensitivity of 1 percent of the pressure range.
      3. (iii)Check the pressure tap for pluggage daily.
      4. (iv)Using a manometer, check gauge calibration quarterly and transducer calibration monthly.
      5. (v)Conduct calibration checks any time the sensor exceeds the manufacturer's specified maximum operating pressure range, or install a new pressure sensor.
      6. (vi)At least monthly, inspect all components for integrity, all electrical connections for continuity, and all mechanical connections for leakage.
   2. (2)For the scrubber water flow rate CPMS, you must:
      1. (i)Locate the flow sensor and other necessary equipment in a position that provides a representative flow and that reduces swirling flow or abnormal velocity distributions due to upstream and downstream disturbances.
      2. (ii)Use a flow sensor with a minimum measurement sensitivity of 2 percent of the flow rate.
      3. (iii)Conduct a flow sensor calibration check at least semiannually according to the manufacturer's instructions.
      4. (iv)At least monthly, inspect all components for integrity, all electrical connections for continuity, and all mechanical connections for leakage.
2. (b)You must install, operate, and maintain each CPMS for a wet scrubber according to the requirements in paragraphs (b)(1) through (3) of this section.
   1. (1)Each CPMS must complete a minimum of one cycle of operation for each successive 15-minute period.
   2. (2)Each CPMS must have valid data for at least 95 percent of every averaging period.
   3. (3)Each CPMS must determine and record the hourly average of all recorded readings.