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8.
Downloading and Understanding DR Data
The DR-7 can store data files containing output data generated through each test. Entering a control
number will store the data into a coma separated values (csv) file located in the DR root folder under
\Programs\Trico\DR. A specialized script can be written through the host lab firmware to load the data
into a given lab data tracking software or into a spread sheet. If using a lab database software, a script will
need to be written to pull these files into lab firmware. Connection to the DR-7 can be completed through
the internet or by USB.
Spread Sheet Example:
Control Number DR Serial # Opaque Dilution DL
DS
PLP
WPC Date time
5063090 103122AB1 N
1 37.65 21.86 26.53 59.5 10/31/2022, 12:24 PM
Example:
Control Number: 05063090
DR Unit ID:
103122AB1
Opaque: N
Dilution: 1
DL: 37.65
DS: 21.86
PLP: 26.53
WPC: 59.50
10/31/2022, 12:24 PM
8.1 – Quantifying DR Data
Quantitative information obtained by ferrography signals can be used as an indication to the
change in the wear situation of a machine in operation. The two readings of D
L
and D
S
correspond to the concentration of large and small particles in the sample. As particles enter a
gradient magnetic field, the DR-7 quantifies particles into two size ranges by reading light
intensity changes at two known locations on the precipitator tube. Magnetic particle separation is
nearly 100% effective for ferromagnetic particles larger than .1µm and virtually all unwanted
carbon and dirt particles are carried away by the oil and heptane solution. Large particles >5µm
are deposited onto the bottom of the precipitator tube within a few millimeters of entering the
magnetic field, while smaller particles 1-2µm will be deposited from the leading edge of the
magnet to approximately 5mm away.
During normal machine operation, microscopic wear particles are formed by the removal or
deformation of interacting surfaces. The wear rate in which particles are generated tends to be
constant when the machine operates normally and in a steady state. Over a period of time the
number of particles in the lubricating oil will reach a dynamic balance and D
L
particles being
generated will equal the number of particles being lost through settling, filtering and other loss
mechanisms. Therefore, under normal steady state conditions D
L
particle size concentrations will
remain similar, while D
S
particles stay suspended, and concentrations gradually rise over time.
(See Figures 8.1 A&B)
