instruNet is the Highest-accuracy System with Low-level Measurements
instruNet is the highest-accuracy data acquisition system for performing
low-level measurements (e.g. ±100mV), as shown in the below table.
Accuracy decreases as you increase sample rate; therefore, when comparing
products, compare their accuracy at the same sample rate.
The instruNet card cage does not contain a noisy processor, which makes it easier to do accurate low-level measurements.
instruNet is Lowest-cost
Standalone
system with
Universal
Inputs
instruNet is the lowest-cost STANDALONE data acquisition system with UNIVERSAL inputs,
as shown in the below table.
Universal inputs support the direct connection to
Voltage,
Current,
Resistance Thermocouple,
Thermistor,
Strain Gage,
Load Cell,
RTD,
and
Accelerometer
sensors; sometimes with the help of one additional shunt resistor.
instruNet does this at $124 per channel with an 8-channel system, with
unprecedented accuracy.
instruNet is Lowest-cost
Card Cage
system with
Universal
Inputs
instruNet is the lowest-cost CARD CAGE system with UNIVERSAL inputs,
as shown in the below table.
Card cages enable modules to be mixed and matched as needed.
The below table is similar to the above table, yet with card cage based systems instead of non-expandable standalone.
instruNet is Lowest-cost
Card Cage
system with
Voltage
Inputs
instruNet is the lowest-cost CARD CAGE system with VOLTAGE inputs,
as shown in the below table.
This is similar to the above table,
yet VOLTAGE-only inputs instead of the more expensive UNIVERSAL Inputs.
instruNet is Lowest-cost system with
Anti-aliasing Filters
instruNet is the lowest-cost data acquisition system
with optional anti-aliasing filters, as shown in the below table.
Anti-aliasing filters eliminate errors caused by high frequencies
that enter the digitizer, as explained
here.
1
Absolute Accuracy Conditions: The system integrates (i.e. averages) for the entire duration of
one sample period (e.g. repeatedly read a/d for 10mSec when digitizing at 100s/sec),
the data acquisition hardware temperature changed 1°C since its last auto-calibration,
and the ambient (e.g. room) temperature is 23°C ± 10C.
2
The USB-9828, and many other Data Translation products, have 0.25uA of input bias current.
This current, multiplied by the source impedance, forms an error. For example, a
350 ohm strain gage you will incur an additional error of ±87uV (350*0.25).
3
Total aggregate sample rate for all channels.
For example, with 1000s/sec aggregate and 4 channels, each channel is digitized at 250s/sec/channel.
4
The DataQ #DI-718 accuracy is 0.25%, which is approximately 10 times less accurate than instruNet.
5
The NI #USB-9219 maximum sample rate is 100s/sec, which is approximately 20 times slower than instruNet. Also, its
cost-per-channel is approximately 3 times higher than instruNet.
6
The NI #USB-6281 is NI's most accurate system, and provides accuracy similar to
instruNet, yet its cost-per-channel is 2 times more with 8 channels, and
≥ 3 times more with ≥ 16 channels.
7
The MCC #USB-2404-UI maximum sample rate is 100s/sec, which is approximately 20 times slower than instruNet.
Also, its cost-per-channel is 2 times more than instruNet.
8
This system provides voltage-only inputs, and does not support the
direct connection to many sensors.
9
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