---
kind: "section"
citation: "40 C.F.R. § 63.8688"
title: "40"
number: "63.8688"
heading: "What are my monitoring installation, operation, and maintenance requirements?"
url: "https://uscodex.org/cfr/40/63.8688"
---

# §63.8688. What are my monitoring installation, operation, and maintenance requirements?

- (a) You must install, operate, and maintain each continuous parameter monitoring system (CPMS) according to the following:
  - (1) The CPMS must complete a minimum of one cycle of operation for each successive 15-minute period.
  - (2) **To determine the 3-hour average, you must—**
    - (i) **Have a minimum of four successive cycles of operation to have a valid hour of data.**
    - (ii) Have valid data from at least three of four equally spaced data values for that hour from a CPMS that is not out-of-control according to your site-specific monitoring plan.
    - (iii) Determine the 3-hour average of all recorded readings for each operating day, except as stated in [§ 63.8690(c)](/cfr/40/63.8690.md?p=c). You must have at least two of the three hourly averages for that period using only hourly average values that are based on valid data (i.e., not from out-of-control periods).
  - (3) You must record the results of each inspection, calibration, and validation check.
- (b) For each temperature monitoring device, you must meet the requirements in [paragraph (a)](#a) of this section and the following:
  - (1) **Locate the temperature sensor in a position that provides a representative temperature.**
  - (2) For a noncryogenic temperature range, use a temperature sensor with a minimum measurement sensitivity of 2.8 °C or 1.0 percent of the temperature value, whichever is larger.
  - (3) If a chart recorder is used, it must have a sensitivity in the minor division of at least 20 °F.
  - (4) **Perform an accuracy check at least semiannually or following an operating parameter deviation—**
    - (i) According to the procedures in the manufacturer's documentation; or
    - (ii) By comparing the sensor output to redundant sensor output; or
    - (iii) By comparing the sensor output to the output from a calibrated temperature measurement device; or
    - (iv) **By comparing the sensor output to the output from a temperature simulator.**
  - (5) Conduct accuracy checks any time the sensor exceeds the manufacturer's specified maximum operating temperature range or install a new temperature sensor.
  - (6) At least quarterly or following an operating parameter deviation, perform visual inspections of components if redundant sensors are not used.
- (c) For each pressure measurement device, you must meet the requirements of [paragraph (a)](#a) of this section and the following:
  - (1) Locate the pressure sensor(s) in, or as close as possible, to a position that provides a representative measurement of the pressure.
  - (2) Use a gauge with a minimum measurement sensitivity of 0.12 kiloPascals or a transducer with a minimum measurement sensitivity of 5 percent of the pressure range.
  - (3) **Check pressure tap pluggage daily.** Perform an accuracy check at least quarterly or following an operating parameter deviation:
    - (i) According to the procedures in the manufacturer's documentation; or
    - (ii) **By comparing the sensor output to redundant sensor output.**
  - (4) Conduct calibration checks any time the sensor exceeds the manufacturer's specified maximum operating pressure range or install a new pressure sensor.
  - (5) At least monthly or following an operating parameter deviation, perform a leak check of all components for integrity, all electrical connections for continuity, and all mechanical connections for leakage.
  - (6) At least quarterly or following an operating parameter deviation, perform visible inspections on all components if redundant sensors are not used.
- (d) For monitoring parameters other than temperature and pressure drop, you must install and operate a CPMS to provide representative measurements of the monitored parameters.
- (e) For each flare, you must install a device (including but not limited to a thermocouple, an ultraviolet beam sensor, or an infrared sensor) capable of continuously detecting the presence of a pilot flame.
- (f) As an option to installing the CPMS specified in [paragraph (a)](#a) of this section, you may install a continuous emissions monitoring system (CEMS) or a continuous opacity monitoring system (COMS) that meets the applicable requirements in [§ 63.8](/cfr/40/63.8.md) according to Table 7 to this subpart and the applicable performance specifications of [40 CFR part 60](/cfr/40/part60.md), appendix B.
- (g) For each monitoring system required in this section, you must develop and make available for inspection by the permitting authority, upon request, a site-specific monitoring plan that addresses the following:
  - (1) Installation of the CPMS, CEMS, or COMS sampling probe or other interface at a measurement location relative to each affected process unit such that the measurement is representative of control of the exhaust emissions (e.g., on or downstream of the last control device);
  - (2) Performance and equipment specifications for the sample interface, the pollutant concentration or parametric signal analyzer, and the data collection and reduction system; and
  - (3) Performance evaluation procedures and acceptance criteria (e.g., calibrations).
- (h) In your site-specific monitoring plan, you must also address the following:
  - (1) Ongoing operation and maintenance procedures in accordance with the general requirements of § [63.8(c)(1)(ii)](/cfr/40/63.8.md?p=c-1-ii), [(c)(3)](/cfr/40/63.8.md?p=c-c-3), [(c)(4)(ii)](/cfr/40/63.8.md?p=c-4-ii), and [(c)(7)](/cfr/40/63.8.md?p=c-c-7) and [(8)](/cfr/40/63.8.md?p=c-c-8);
  - (2) Ongoing data quality assurance procedures in accordance with the general requirements of [§ 63.8(d)](/cfr/40/63.8.md?p=d); and
  - (3) Ongoing recordkeeping and reporting procedures in accordance with §§ [63.8693](/cfr/40/63.8693.md) and [63.8694](/cfr/40/63.8694.md) and the general requirements of § [63.10(e)(1)](/cfr/40/63.10.md?p=e-1) and [(e)(2)(i)](/cfr/40/63.10.md?p=e-2-i).
- (i) You must conduct a performance evaluation of each CPMS, CEMS, or COMS in accordance with your site-specific monitoring plan.
- (j) You must operate and maintain the CPMS, CEMS, or COMS in continuous operation according to the site-specific monitoring plan.

## Notes

### Amendments

[68 FR 24577, May 7, 2003, as amended at 85 FR 14549, Mar. 12, 2020]

### Source

Source: 68 FR 24577, May 7, 2003, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.

### Amendments

[68 FR 24577, May 7, 2003, as amended at 85 FR 14549, Mar. 12, 2020]