REF is an indication of the strength of signal measured within the colorimeter. A low REF count can indicate a weak/failing colorimeter. Reference counts should be checked after a thorough cleaning of the colorimeter measurement cell, as a dirty colorimeter will also cause low reference counts.
Reference counts of 10,000 to 50,000 indicate a clean colorimeter which is in good condition. Below 10,000 counts indicate a cleaning is required. If the counts remain below 10,000 after cleaning, this is an indication that the component is beginning to weaken. We recommend replacement if counts are below 10,000, but system will continue to measure accurately below this level. As the reference count continues to drop, the unit will generate several system alarms:
System Alarm REF counts
A/D ERROR 0
LED ERROR <100
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