Zcorr Digital Correlating Logger

ZCorr Digital Correlating Loggers

Advantages of ZCorr Correlating Loggers

Performs correlations exactly like a correlator
– Pinpoints exact distance to leak
Can operate at night in "Overnight Survey"
– Less traffic and usage noise
Multiple loggers survey large areas for leaks
– 8, 16, or 32 loggers over miles of pipe
Can turn "ON" multiple times with hours between recordings
– Best chance to get leak sounds without usage noises
Can find smaller leaks at night
– less traffic and usage noise
Even more sensitive than human ear
User can listen to the actual leak sounds for 60 seconds for each recording (unfiltered)

ZCorr Sensor

Advantages of Automatic Leak Frequency Analysis (ALFA)

Accurate registration and pinpointing of each leak sound occurs automatically with every recording
Tracks the patterns of the leak sound over time to "tune in" to the true leak sound signal
Digital signal processing isolates (multiple) leak sounds individually at each logger, statistically optimizing their correlation at each possible value of time delay
No fixed high or low filters are needed for matching the audio frequencies at two correlating loggers
Can extract the true leak sounds from each recording even when louder noises are present at the same audio frequencies

The Solution is in the ZCorr Software

Analysis of All Correlations Found

Click a Thumbnail, See the 8 Best Correlations.

8 Best Correlations

Above: Many correlations at many loggers. One leak or many?

Click Listen. Logger No. 4 much louder (below).

Logger Number 4 louder

Click Play and listen to the leak for 60 seconds.

Correlation at 2:15 AM but not at 1:15 AM or 3:15 AM

Correlation at 2:15 AM but not at 1:15 AM or 3:15 AM. Answer: Usage at service

The Sound Level Graph (above) is for Logger no. 7 (high-lighted in the Leak Index Graph).
The Leak Index shows very little sound, and the Graph shows usage noise (meter) during the 2:15 AM recording.

Leak Index Graph

The Leak Index Graph (bars) shows good leak sounds at Loggers no. 1, 2, and 3.
The Sound Level Graph shows a very steady leak noise for Logger no. 3.

Technical Specifications ZCorr Digital Correlating Loggers

Logger

Enclosure: Aluminum, cylindrical
Protection: IP68, fully submersible
Dimensions: 2.25" diameter x 4.5" (5.7 cm x 11.4 cm)
Weight: 1 lb (450 g)
Mounting: Magnet, 40 lbs (18 kg) pull force • Operating temperature range: -20 to +140°F (-30 to +60°C)
Power source: Lithium battery, 5-year life, factory-replaceable, non-rechargeable
Sensor:
– High-resolution electronic accelerometer
– Shockproof to 6,000 g
– Sensitivity: 1 V/g
– Resolution: 0.25 ?g /?Hz
Data Acquisition:
– Frequency range: 1-3,000 Hz
– Signal range: sub 1 ?g – 20 mg
– Digital resolution: 20 bits