Null Data Codes in old format
| Qualifier Code | Old Null Data Code | Item Description |
|---|---|---|
| AA | 9967 | SAMPLE PRESSURE OUT OF LIMITS |
| AB | 9968 | TECHNICIAN UNAVAILABLE |
| AC | 9969 | CONSTRUCTION/REPAIRS IN AREA |
| AD | 9970 | SHELTER STORM DAMAGE |
| AE | 9971 | SHELTER TEMPERATURE OUTSIDE LIMITS |
| AF | 9972 | SCHEDULED BUT NOT COLLECTED |
| AG | 9973 | SAMPLE TIME OUT OF LIMITS |
| AH | 9974 | SAMPLE FLOW RATE OUT OF LIMITS |
| AI | 9975 | INSUFFICIENT DATA (CAN'T CALCULATE) |
| AJ | 9976 | FILTER DAMAGE |
| AK | 9977 | FILTER LEAK |
| AL | 9978 | VOIDED BY OPERATOR |
| AM | 9979 | MISCELLANEOUS VOID |
| AN | 9980 | MACHINE MALFUNCTION |
| AO | 9981 | BAD WEATHER |
| AP | 9982 | VANDALISM |
| AQ | 9983 | COLLECTION ERROR |
| AR | 9984 | LAB ERROR |
| AS | 9985 | POOR QUALITY ASSURANCE RESULTS |
| AT | 9986 | CALIBRATION |
| AU | 9987 | MONITORING WAIVED |
| AV | 9988 | POWER FAILURE (POWR) |
| AW | 9989 | WILDLIFE DAMAGE |
| AX | 9990 | PRECISION CHECK (PREC) |
| AY | 9991 | Q C CONTROL POINTS (ZERO/SPAN) |
| AZ | 9992 | Q C AUDIT (AUDT) |
| BA | 9993 | MAINTENANCE/ROUTINE REPAIRS |
| BB | 9994 | UNABLE TO REACH SITE |
| BC | 9995 | MULTI-POINT CALIBRATION |
| BD | 9996 | AUTO CALIBRATION |
| BE | 9997 | BUILDING/SITE REPAIR |
| BF | 9998 | PRECISION/ZERO/SPAN |
| BG | 9966 | MISSING OZONE DATA NOT LIKELY TO EXCEED LEVEL OF STANDARD |
| BH | 9965 | Interference/co-elution |
| BI | 9964 | Lost or damaged in transit |
| BJ | 9963 | Operator Error |
| BK | 9962 | Site computer/data logger down |
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