Opacimeter response Clause Samples
Opacimeter response. 3.7.1 The response time of the electrical measuring circuit, being the time necessary for the indicating dial to reach 90 per cent of full-scale deflection on insertion of a screen fully obscuring the photoelectric cell, shall be 0.9 to 1.1 second.
3.7.2 The damping of the electrical measuring circuit shall be such that the initial overswing beyond the final steady reading after any momentary variation in input (e.g. the calibration screen) does not exceed 4 per cent of that reading in linear scale units.
3.7.3 The response time of the opacimeter which is due to physical phenomena in the smoke chamber is the time taken from the start of the gas entering the chamber to complete filling of the smoke chamber; it shall not exceed 0.4 second.
3.7.4 These provisions shall apply solely to opacimeters used to measure opacity under free acceleration.
Opacimeter response. 3.7.1 The response time of the electrical measuring circuit, being the time necessary for the indicating dial to reach 90 per cent of full-scale deflection on insertion of a screen fully obscuring the photoelectric cell, shall be 0.9 to 1.1 second.
3.7.2 The damping of the electrical measuring circuit shall be such that the initial overswing beyond the final steady reading after any momentary variation in input (e.g. the calibration screen) does not exceed 4 per cent of that reading in linear scale units.