Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been allowed to stabilize in the standard atmospheric conditions for testing as described in IEC 60068-1 as follows:

　

d) temperature ; (15 to 35)℃

　

e) relative humidity (25 to 75) %

　

f) air pressure : (86 to 106) kPa

　

NOTE　If variations in these parameters have a significant effect on a measurement, then such variations should be kept to a minimum during a series of measurements carried out as part of one test on one specimen.

　

　

If a specific tolerance or deviation limit is not specified in a requirement or test procedure a deviation limit of ± 5% shall be applied.

　

　

The response point shall be measured by exposing the detector to the radiation from a suitable flame source and determining the greatest distance at which the detector will reliably produce an alarm condition within a time of 30 s.

　

　

The test apparatus shall be as described in annex A.

　

The design and construction of the apparatus, and the surfaces surrounding the test area, shall be such that no significant radiation from the source reaches the detector apart from that which has passed through the aperture. (This means for example that there shall be no reflection of radiation from the walls or other parts of the apparatus, and no spurious radiation from hot flue gases or hot surfaces around the burner.) Throughout this test method it is necessary to align the detector relative to its optical axis and to measure distances relative to the plane of the detector sensing element(s). If the detector does not have a well-defined optical axis then the manufacturer shall nominate an optical axis for the purposes of this test method. The position of this axis relative to an easily identifiable plane on the detector shall be noted in the test report.

　

Similarly, if the detector sensing elements do not lie in a well-defined plane then the manufacturer shall nominate a plane for the purposes of this test method. The position of this plane relative to an easily identifiable plane on the detector shall be noted in the test report.

　

　

A suitable area for the aperture shall be determined experimentally before the commencement of the test programme such that the response point of one detector, chosen at random from the specimens submitted for test, lies within the range 1300mm to 1700 mm. The size and shape of the aperture used shall be recorded and shall be kept constant throughout the test programme. For detectors having adjustable sensitivity, and whose adjustment range covers more than one sensitivity class, it will be necessary to determine an appropriate aperture size for each sensitivity class of the detector.

　

　

After determining a suitable aperture size, and before any determination of response points, the irradiance on the optical axis of the source shall be measured using the radiometer in accordance with A.5. This measurement shall be carried out with no modulation of the source and with the aperture unobstructed. The measured value of irradiance shall be recorded and used as a reference throughout the test programme to verify that the source radiance has not varied by more than 5%.

　

　

The specimen shall be connected to its supply and indicating equipment and shall be allowed to stabilize for a period of 15 min or for a time specified by the manufacturer. During this stabilization period the specimen shall be shielded, using the shutter in accordance with A.3, from all sources of radiation which may affect the determination of the response point.

　

Before commencing any measurement of response point the burner shall be allowed to reach a stable working condition.

　

The distance of the specimen from the source shall be varied and at each distance the detector shall be exposed to the source for 30 s using the shutter. The response point D is the greatest distance, measured between the aperture and the plane of the specimen sensing element(s), at which the detector will reliably produce an alarm response within each 30 s exposure. If the detector response is known to be dependent on previous exposure to radiation then sufficient time shall be allowed before each exposure to ensure that previous exposures do not substantially affect the measurement of the response point.

　

For detectors having stochastic response behavior each value of D shall come from at least six repetitions of each measurement, D being the mean value of these repetitions. Repetitions shall continue until an additional value changes the average value of D by less than 5%.

　

　

Where the test procedure calls for a reduced functional test, the detector shall be exposed to a source of radiation which is sufficient to cause an alarm response from the detector. The nature of the source used and the duration of the exposure shall be appropriate to the product in question.

　

　

Eight heads and eight bases, or for non-detachable detectors, eight complete detectors shall be provided for testing compliance with this standard.

　

The specimens shall be representative of the manufacturer's normal production with regard to their construction and calibration.

　

NOTE　This implies that the mean response point of the eight specimens, found in the reproducibility test should also represent the production mean, and that the limits specified in the reproducibility test should also be applicable to the manufacturer's production.

　

　

The detectors shall be tested according to the test schedule given in Table 1. After the reproducibility test the four specimens having the largest value of response point (at the highest sensitivity setting) shall be numbered 1 to 4 and the remainder shall be numbered 5 to 8.

　

　

　

　

　

The response point of each of the test specimens shall be measured in accordance with 5.1.3 and each value of D shall be recorded. For detectors having adjustable sensitivity and whose range of adjustment covers more than one sensitivity class, the measurement shall be repeated for each marked class. For each class setting, the highest value of D shall be designated Dmax, the lowest value of D shall be designated Dmin, and the mean value of D designated Dmean.

　

　

For each class setting, the ratio Dmax/Dmean not be greater than 1,15 and the ratio Dmean/Dmin shall not be greater than 1,22.

　

　

　

The response point of the specimen shall be measured in accordance with 5.1.3, six times. The maximum response point shall be designated Dmax and the minimum value designated Dmin.

　

　

The ratio of the response points Dmax/Dmim shall not be greater than 1,14.

　

　

　

The detector shall be mounted on the optical bench with its optical axis coincident with the source optical axis as shown in Figure 1. The detector shall then be rotated through an angle a about an axis normal to the optical axis and passing through the point of intersection of the optical axis and the plane of the sensing element(s). The response point of the detector shall be measured for:

　

　

where αmax is the maximum 1/2-angle of reception specified for that detector type by the manufacturer.

　

With the angle a set to αmax the specimen shall be rotated about its optical axis through an angle β and the response point measured a further seven times for β=45°,90°,135°,180°, 225°, 270°, 315°. The maximum value of response point recorded at any angle in this test and that measured for the same specimen in the reproducibility test shall be designated Dmax and the minimum value designated Dmin.

　

　

The ratio of the response points Dmax/Dmin shall not be greater than [2,00] 1,41.