Calibrations–Part 60 vs 75
Calibrations are an integral part of operating a CEM system effectively. However, depending on which regulations your site falls under, this process can be subject to different requirements. It is crucial that you understand these differences, especially if you are a site that is subject to both regulations, in order to maintain compliance and minimize downtime. Below are important ways in which Part 60 calibrations differ from Part 75 calibrations.
Drift Specifications
Part 60 Part 75
NOx 2.5% span 5% span OR 5ppm (if range <50ppm) OR 10ppm (if range >50<200ppm)
SO2 2.5% span 5% span OR 5ppm (if range <50ppm) OR 10ppm (if range >50<200ppm)
CO 5% span None
NH3 2.5% span None
O2 0.5% span 1%
CO2 0.5% span 1%
Velocity 3% span 6%
Opacity 2% span None
*References: 40CFR60 App_B Spec 1-4; 40CFR75 App_B § 2.1.4
Out of Control Criteria
Part 60 Part 75
Single Failed Cal 4x drift spec. in a single calibration 1x drift spec. in a single calibration
5 Day Drift Limit 5th consecutive cal at 2x drift spec. is OOC None
*References: 40CFR60 App_F § 4.3.1; 40CFR75 App_B § 2.1.4
Data Invalidation
Part 60 Part 75
Failed Calibration OOC back to last passing cal until next passing cal OOC from failed cal until next passing cal
Missed Calibration After approximately 24 hours, data is OOC until next passing cal After 26 hours, data is OOC until next passing cal
*References: 40CFR60 app. F § 4.3.1; 40CFR75 app. B § 2.1.5
Daily Calibration Hourly Requirements
| Part 60 | Part 75 | |
|---|---|---|
| Daily Calibration | Approximately every 24 hours | Every 26 hours |
| Grace Period | None | 8 hours after startup** |
*References: 40CFR60 App_F § 4.1; 40CFR 75 App_B § 2.1.5
**several requirements apply for this exception
Range Requirements
Part 60 Part 75
Zero 0-20% span 0-20% span
Mid None 50-60% span
High 50-100% span 80-100% span (can use mid in lieu of high if more representative)
*References: 40CFR60.13.d; 40CFR75 App_A § 5.2
As always, if you have questions on which requirements apply to your facility and what that means for you, feel free to contact us.