Application Note

Probe Permeameter Machineusing MCC 118 and MCC 134 with Raspberry Pi®
Introduction
RO Scientific is a small engineering company as wellas the MCC distributor in Romania and specializes
in providing custom DAQ solutions. With expertisein both system design and software development,
customers turn to them when commercially available
solutions are either too expensive and/or do not fully
suit their needs.
One such customer had a requirement for developing an automated permeameter machine. Accurate
rock permeability measurements are critical for theoil and gas industry as the costly decision to drill ina particular spot heavily relies on such permeability
measurements performed on prospective core samples.
The developed product is a fully automatic, dual steady/unsteady state, 2D predefined and arbitrary measurement pattern permeameter. The aim was to design adevice capable of providing fast and reliable permeability measurements, with unprecedented accuracy
and repeatability over large core samples.

Data is sent via WiFi to a remote touch screen interface
where the operator can view gas pressure, temperature,and flow data in real time.

The Challenge
The process of measuring the permeability in coresamples continues to be more like an art that lies on
the talent and expertise of the technician that performs
the measurement. The whole process is labor intensive
and time consuming. RO Scientific’s customer wanted
to automate this process, as if it was performed by ahuman expert, and do so in fraction of the time.

The Solution
RO Scientific decided on the Raspberry Pi platform
because they needed something as small as possible yetcapable of providing enough computational power toperform some basic machine vision, do real time dataacquisition and processing, and transfer the outcome
via Wi-Fi to a remote interface. The MCC DAQ HATs
were selected because of their ability to make accurate
measurements at high speeds.

The Probe Permeameter machine makes measurements
in core samples using an X-Y control system with under
one millimeter precision. A Raspberry Pi 4 board is at
the heart of the solution, providing enough processing
power for the machine vision and data acquisition andcontrol functions.

The completed machine consists of a high-resolution
camera, an X-Y table, controllers, a Raspberry Pi 4,and the MCC 118 and MCC 134 DAQ HATs. The HATs
measure four pressure sensors, one high-precision
temperature sensor, and two thermocouples formeasuring slow changing temperature measurements,
like ambient temperature.

The system was programmed using the open-source
MCC Universal Library for Linux®. It was critical for
RO Scientific be in full control of the software so they
can deliver updates any time there is a change in thecustomer’s needs.

1Measurement Computing • 10 Commerce Way • Norton, MA 02766 • (508) 946-5100 • info@mccdaq.com • mccdaq.com

OperationResultUsing a hi-res camera, the system scans the measurement table, determining the edges of the rocksample. A pneumatic actuator then lowers a probe
to the sample surface and a gas (typically nitrogen)is injected into the rock sample. Pressure is measured
at several points and temperature data is logged. Gas
viscosity is determined. A fast-responding pressure
sensor makes measurements at 10 kS/s, monitoring
the pressure decay. From this pressure decay curve, in
conjunction with the other pressure and temperature
measurements, the sample permeability is calculated.
This process is repeated in several locations within
the sample.

RO Scientific used the latest permeability measurement research and transposed the decision-making
process into code. The outcome was a 90% decrease in
the overall measurement time and the measurements
proved to be as accurate as when performed by a human expert, and equally important, made the wholeprocess repeatable.
Sandrino Marinescu
RO SCIENTIFIC SRL
4 Decebal Alley, Bld. B6 / 10,700231 Iasi, Romania
info@roscientific.com

2Measurement Computing • 10 Commerce Way • Norton, MA 02766 • (508) 946-5100 • info@mccdaq.com • mccdaq.com