Add link to corresponding ticket in ph-meter card

external/lab/utilization-of-pH-meter/utilization-of-pH-meter.md

@@ -92,4 +92,4 @@ The calibration standard solutions are of pH 4, 7 and 10.
 
 4. Contact the quality assistant if the logbook is full.
 
-5. Would you notice any issue with the instrument, create a ticket.
+5. Would you notice any issue with the instrument, [create a ticket](https://service.uni.lu/sp?id=sc_cat_item&sys_id=be0873f8db7070505c72ef3c0b96199f&sysparm_category=af924f17dbac38105c72ef3c0b96194b).
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