Universal User Guide, Rev L, February 2022
47
8.3
Accelerometer
The accelerometer is a three-axis micro-electro-mechanical system (MEMS) inertial sensor. The data can
record for tilt-quasi-static orientation calculations as well as activity monitoring and
recording “g
-
forces”
.
The accelerometer measures projections of the acceleration vector (a-g) onto the MAT-1 axes. Thus, the
vector sum of the X, Y and Z axes will register a magnitude of approximately 1 g while at rest on the
surface of the earth.
The sensor operates at 1600 Hz with 12-bits of resolution and holds the most recent values in a 32 value
first-in-first-out buffer (FIFO). The MAT-1 reads the contents of the FIFO buffer for each measurement
and averages the results. The recorded value is stored as a 14-bit value. The result of this process is that
there is both an increase in resolution and a reduction in noise.
8.4
Thermistor
The logger has an instrumentation-grade Negative Temperature Coefficient thermistor. The resistance
measurement is made with an instrument-grade 16-bit analog to digital converter (A/D).
The temperature sensor is located approximately in the center of the logger. The sensor has a low-pass
filter with a cut-off frequency of 16 Hz, which substantially reduces noise from 50/60Hz electromagnetic
interference. The sensor has a relatively slow time response, making it very good at averaging ambient
temperatures.
The accuracy and resolution of the sensor is dependent on the temperature. The logge
r has a “standard
range” and an “extended range”.
The accuracy and resolution are higher in the “standard range” than in
the “extended range”.
All loggers are capable of recording temperature in both ranges. Consult the
Product Data Sheet
for details.
9
Logger Maintenance
9.1
O-Ring Care
The MAT-1 Logger will be damaged if water enters the housing. It is
very important that the O-ring be kept clean and in good condition.
Hair, sand, and grit can all cause leaks and should be wiped away with
a lint-free cloth. The O-ring comes pre-lubricated from the factory
and should be periodically re-lubricated with O-ring lubricant.
Tip: Do not over tighten the end cap. Hand tighten only. Over
torquing the end cap will not increase the sealing characteristics of
the O-ring and may make the cap difficult to re-open.
The O-ring is made of EPDM rubber. EPDM performs well in water but
is not compatible with petroleum-based materials.
Lubricate O-ring
Содержание MAT-1 Data Logger
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