---
kind: "section"
citation: "40 C.F.R. § 1065.290"
title: "40"
number: "1065.290"
heading: "PM gravimetric balance."
url: "https://uscodex.org/cfr/40/1065.290"
---

# §1065.290. PM gravimetric balance.

- (a) **Application.** Use a balance to weigh net PM on a sample medium for laboratory testing.
- (b) **Component requirements.** We recommend that you use a balance that meets the specifications in Table 1 of [§ 1065.205](/cfr/40/1065.205.md). Note that your balance-based system must meet the linearity verification in [§ 1065.307](/cfr/40/1065.307.md). If the balance uses internal calibration weights for routine spanning and the weights do not meet the specifications in [§ 1065.790](/cfr/40/1065.790.md), the weights must be verified independently with external calibration weights meeting the requirements of [§ 1065.790](/cfr/40/1065.790.md). While you may also use an inertial balance to measure PM, as described in [§ 1065.295](/cfr/40/1065.295.md), use a reference procedure based on a gravimetric balance for comparison with any proposed alternate measurement procedure under [§ 1065.10](/cfr/40/1065.10.md).
- (c) **Pan design.** We recommend that you use a balance pan designed to minimize corner loading of the balance, as follows:
  - (1) **Use a pan that centers the PM sample media (such as a filter) on the weighing pan.** For example, use a pan in the shape of a cross that has upswept tips that center the PM sample media on the pan.
  - (2) **Use a pan that positions the PM sample as low as possible.**
- (d) **Balance configuration.** Configure the balance for optimum settling time and stability at your location.

## Notes

### Amendments

[73 FR 37300, June 30, 2008, as amended at 75 FR 68462, Nov. 8, 2010]

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 70 FR 40516, July 13, 2005, unless otherwise noted.

### Amendments

[73 FR 37300, June 30, 2008, as amended at 75 FR 68462, Nov. 8, 2010]