Regulations last checked for updates: Nov 22, 2024

Title 40 - Protection of Environment last revised: Nov 20, 2024
Appendix - Table 4 to Subpart NNNa of Part 60—Calibration and Quality Control Requirements for Continuous Parameter Monitoring System (CPMS)
If you monitor this
parameter . . .
Your accuracy requirements
are . . .
And your calibration requirements
are . . .
1. Temperaturea. ± 1 percent over the normal range of temperature measured or 2.8 degrees Celsius (5 degrees Fahrenheit), whichever is greater, for non-cryogenic temperature ranges
b. ± 2.5 percent over the normal range of temperature measured or 2.8 degrees Celsius (5 degrees Fahrenheit), whichever is greater, for cryogenic temperature ranges
c. Performance evaluation annually and following any period of more than 24 hours throughout which the temperature exceeded the maximum rated temperature of the sensor, or the data recorder was off scale.
d. Visual inspections and checks of CPMS operation every 3 months, unless the CPMS has a redundant temperature sensor.
e. Selection of a representative measurement location.
2. Flow Ratea. ± 5 percent over the normal range of flow measured or 1.9 liters per minute (0.5 gallons per minute), whichever is greater, for liquid flow rate
b. ± 5 percent over the normal range of flow measured or 280 liters per minute (10 cubic feet per minute), whichever is greater, for gas flow rate
c. ± 5 percent over the normal range measured for mass flow rate
d. Performance evaluation annually and following any period of more than 24 hours throughout which the flow rate exceeded the maximum rated flow rate of the sensor, or the data recorder was off scale.
e. Checks of all mechanical connections for leakage monthly.
f. Visual inspections and checks of CPMS operation every 3 months, unless the CPMS has a redundant flow sensor.
g. Selection of a representative measurement location where swirling flow or abnormal velocity distributions due to upstream and downstream disturbances at the point of measurement are minimized.
3. pHa. ± 0.2 pH unitsb. Performance evaluation annually. Conduct a two-point calibration with one of the two buffer solutions having a pH within 1 of the pH of the operating limit.
c. Visual inspections and checks of CPMS operation every 3 months, unless the CPMS has a redundant pH sensor.
d. Select a measurement location that provides a representative sample of scrubber effluent and that ensures the fluid is properly mixed.
4. Specific Gravitya. ± 0.02 specific gravity unitsb. Performance evaluation annually.
c. Visual inspections and checks of CPMS operation every 3 months, unless the CPMS has a redundant specific gravity sensor.
d. Select a measurement location that provides a representative sample of specific gravity of the absorbing liquid effluent and that ensures the fluid is properly mixed.
authority: 42 U.S.C. 7401
source: 36 FR 24877, Dec. 23, 1971, unless otherwise noted.