EN 932-5-2012 pdf download.Tests for general properties of aggregates-Part 5 : Common equipment and calibration.
An ice point or another appropriate sgle port check of thermometers shall be carñed out six months after first being brought frito use, then annually fri addition to the five-year cahbrabon Interval requirement.
If themiacouples are used. e.g. for verifying oven temperatures, they shall be calibrated against a reference thermocouple. reference platinum resistance thermometer or reference hquid-in-ass thermometer at least once a year
5.2.3.5 Dimensional measuring Instruments
Steel rules shall be checked before use for readabibty and for wear at their ends at least once a year.
Vernier calhpers and momeIers shalt be calibrated at least once a year against reference gauge blocks and reference ring gauges if appropriate.
Deal gauges shall be calibrated at least once a year against a calibrated meaometer device, or In a comparator frame usrng gauge blocks or length bars.
5.2.3.5 TImers
Tmimg devices such as stopdocks and stopwalches shalt be calibrated at least once a year to 600 i I S.
52.3.7 VolumetrIc glassware
The capacity of volumetric glassware shall be checked by Weighing the amount of boded or de-aired water that the vessel contains or delivers at a measured temperature. A calibrated balance and the temperature correction tables in ISO 4788 shall be used. Volumetnc glassware shall be rechecked on a rolling pro’amme at least once every five years
5.2.3.8 DensIty hydrom.teri
Density hydrometers shall be calibrated before first use arid shall be re-cabbrated or replaced at intervals not
exceeding live years.
5.2.4 Checking of other instruments
5.2.4.1 General
Routine checking of other instruments shall be carried out at intervals that are based on usage and on the anatysie of documented checkrng data to ensure the required accuracy is not lost between checks. For convenience, the check intervals for other Instruments specified In 5.242 to 52.4.11 are summanted In Table 4.
The time interval between checking may be reduced or extended, depending 4on the stablity of the results.
Whenever a change r accuracy of an instrument is suspected, or when an instrument has been mishandled, repaired, dismantled, adustod or overhaied, It shah be re-checked before further use.
5.2.42 Ovens
The temperature profile of an empty oven shah be checked before first use and after any major repair or reptacement of heater elements and/or thermostat,
The set temperature at the mid-point of the usable oven space of an empty oven shall be checked by means at a calibrated temperature measuring device at least once a year
NOTE The lolng procedure is a suitable method for verdyw’ig the en prose. but other procedures may be used providing can be demonstrated that suitably aocurete deta can be obtaned Eight calibrated temperature meesurvig devices should be used Wi conuriction with the m.d-point device , measure the temperature profile r the usable oven space Four should be bcald Wi the upper one-thWd of the oven ipce and tour should be bcated In the lower o.w-thvd of the oven space Each of the eight cahbiated temperature devices should be located — least 75 mm from the sides of the oven chamber The temperature recorded at each of the eight powts should be w.thi t 5 C of the set temperature as measured the mid-point of the usable oven space.
5.2.4.3 Constant temperature bath
Constant temperature water baths shall be checked at least once a year by using a calibrated immersn thermometer at several podnts within the working area at’ the bath and observing the temperature when it becomes stable
NOTE For a given steady room temperature the wter temperature control setting can be cahbrad against venous water temperatures by repeating th, procedure over a rang. of settings
5.2.4.4 Test slvs
5.2.4.4.1 Visual checks
M sieves shall be checked by the operator before each use. A detailed visual check shaH be made of the condition of every sieve at regular intervals depending on use
The visual checks shall identify any damage. scoring, or blinding which is likely to affect the performance of the sieve. If any doubt exists, a measurement or performance check, as appropriate, shall be carned out before further use.
Test sieves which fail visual checks shall be clearly marked as such, and be either discarded or used as guard sieves where appropflate.
5.2.4.4.2 Perforated plate test sieves
The apertures of perforated plate test sieves shall be checked at least once every two years. and more frequently depending on use, according to one of the following procedures:
– by measurement in accordance with ISO 3310-2 (reference method),
by peilorn’iance check in accordance with the method descrlbed in Annex A, by a check gauge method in accordance with Annex B.
In case 04 doubt, the reference method shall be used
NOTE Opbc methods can abo be used as a method of exwnetion
5.2.4.4.3 Woven metal wire cloth test sieves
The apertures at woven wire cloth test sieves shall be checked at least once every year. and more frequently depending on use, according to one of the following procedures:EN 932-5-2012 pdf download.
EN 932-5-2012 pdf download
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