AWS C2.21M/C2.21:2015 pdf free download

AWS C2.21M/C2.21:2015 pdf free download.Specification for Thermal Spray Equipment Performance Verification.
The terms standard temperature and pressure (STP) and normal temperature and pressure (NTP are not always provided during application of this standard since they may create confusion about the values used for component or system calibration. If STP. NTh or other similar acronym or terminology is used at any time, the values on which the standard is based shall be provided. The values of temperature and pressure used to calibrate various equipment components may not be consistent between devices or manufacturers. For example, a temperature of 0°C [32°F1. 15°C [59°F1, 20°C 168°FL 25°C 177°F1 or other may have been used to calibrate the device under test (DUT). It is almost certain, the calibration standard does not match the operating environment. Therefore, it is important to know what the standard is and how the difference between the measuring instrument and DUT will affect the calibration.
Annex A provides formulas for comparing or converting values. Please note the gas property values provided for reference in Table A.2 are based on 0°C 132°F1 and the values provided for reference in Table A.3 are based on 20°C 168°F1.
When the as-found variance appears to exceed 2% and no obvious issues that might affect performance (e.g.. mechanical problems. contamination, or leakage) are evident, the Inspector should take extra precaution before affecting changes to DUT. It is important to verify the error is not based on a mismatch of calibration standards prior to implementing significant changes or adjustments.
6.1.1 Ambient Temperature. Thermal spray processes utilize thermal and kinetic energy in the formation of coatings. Thermal efficiency of the process can be significantly affected by the ambient air temperature and other possible influences such as the process cooling water temperature.
6.1.1.1 Air Temperature. The equipment niay be influenced by both the ambient air temperature and forced air c(x)ling efficiency. The ambient air temperature is determined by taking at least two temperature measurements within I ni 139 ml of the equipment during which the measuring instrument is protected from drafts and abnormal heating. The mean value of the temperature reading is the teiiiperature of the ambient air.
In the case of forced air-cooled equipment, the measuring devices are placed where the air enters he cooling system. Where possible, temperatures are recorded while the equipment is in operation and after shutdown.
On (hose parts where the recording of temperature is fbi possible while the equipment is in operation. temperatures are taken after shutdown as described below. Whenever a sufficient time has elapsed between the instant of shutdown and the time of tinal temperature measurement to permit the temperature to fall, suitable corrections are applied to obtain as nearly as practical the temperature at the instant of shutdown. This may be done by marking the time at the instant of shutdown. Successive temperature readings are taken, and the elapsed time from shutdown noted for each. AWS C2.21M/C2.21:2015 pdf free download.