The COMBO tool is used to make high-resolution pressure and temperature measurements in producing wells, and also provides digital wireline telemetry/power supply functions.
It consists of a sensor section that samples the temperature of fluids flowing past the tool and a unique silicon-on-sapphire strain-gauge pressure sensor, together with an electronics section that digitizes the sensor outputs and transmits the data on high-speed digital telemetry up the monocable wireline.
The tool also interrogates up to 11 other compatible tools stacked below the Combo at a rate of 16 times per second.
The graph below shows typical pressure measurement accuracy of the Combo Tool. The accuracy specification of the dead weight tester is +/- 5 PSI.