Apex Gauge

Reservoir Group has the most comprehensive line-up of Piezo Memory Gauges available anywhere.

The gauge is supplied in monitor mode, testing sensor readings every two minutes and automatically starts recording to memory if user-programmed thresholds are exceeded. Data is time-stamped and stored in memory at a programmed sample rate. At the end of the survey, the gauge stops automatically when readings fall below set thresholds.

For easy shipping, the Battery Pack is classed as non-dangerous goods. The Battery Pack is detachable and can be changed by the operator without special tools, so it’s ideal for use in remote locations. The gauge incorporates a removable switch that, when removed, prevents inadvertent recording whilst being stored in warmer conditions where programmed thresholds may be exceeded.


  • Fully automatic – no operator input to record data
  • All data stored with real time values for easy analysis
  • Very large 4,000,000 data set memory provides long duration recording at fast sample rates
  • Innovative electronics dramatically reduces power consumption
  • Simple Battery Pack change – ideal in remote locations
  • Easy shipping – no dangerous goods paperwork required
  • Can be used as a Surface Memory Gauge


  • Casing leak detection
  • Frac monitoring
  • Gradient surveys
  • Gauge carrier operations
  • Pressure build-up or draw-down tests
  • Production surveys
  • Reservoir evaluation, well testing and DST
  • Slickline operations
  • Stimulation monitoring
  • Static, flowing and build-up surveys
  • Temperature logging


Maximum external pressure Must not exceed sensor range or 15 ksi Max
Sensor range 2 options, 8.6 ksi and 15 ksi
Sensor type Piezo-resistive
Accuracy ± 0.06% FSO
Accuracy typical
± 0.04% FSO
0.1 psi
Maximum temperature
Must not exceed 150°C
Operating range
0 to 150°C
± 1.0°C
Accuracy typical
± 0.5°C
Battery type
AA Lithium
Operating voltage
3.6 to 3.9 V
Battery life*
Better than 1 Year
Sampling interval 1 to 600 seconds
Capacity 4,000,000 data sets
Record contents
Real time, pressure, temperature
Materials SS 17-4 PH, Sub K500 Monel
Standard or H2S