Omega Engineering OMB-DBK-34A, User Manual

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DBK16
2-Channel Strain-Gage Card
Overview …… 1
Hardware Setup …… 2
Card Connection …… 2
Excitation …… 5
Card Configuration …… 6
Calibrating DBK16, for Daq Devices …… 9
DaqBook/100 Series & /200 Series and DaqBoard [ISA type] Configuration …… 10
DaqBook/2000 and DaqBoard/2000 Series Configuration …… 10
Software Setup …… 11
GageCal Program …… 11
Example …… 12
Using the DBK16 with 3-Wire Strain Gages …… 13
Calibrating DBK16 and DBK43A for LogBooks …… 15
Overview …… 15
Calibration Methods …… 16
Procedures Common to All Calibration Steps (Required) …… 17
Nameplate Calibration and Manual Calibration …… 20
Channel Calibration Procedure …… 23
2-Point Calibration …… 26
Shunt Calibration …… 28
Creating a Units Conversion Transfer Function …… 30
Periodic Calibration Without Trimpots …… 31
DBK16 – Specifications …… 31
Reference Notes :
o
Chapter 2 includes pinouts for P1, P2, P3, and P4. Refer to pinouts applicable to your
system, as needed.
o
In regard to calculating system power requirements, refer to DBK Basics located near
the front of this manual.
Overview
The DBK16 will condition signals from most types of bridge circuit configuration transducers that have
a signal output of less than 50 mV. Strain gages and load cells are common types of these transducers.
For half- and quarter-bridge strain gages, the DBK16 can accommodate user-supplied bridge completion
resistors that complete the bridge circuit.
The bridge circuit must be complete for the DBK16 to operate correctly.
Each channel of the DBK16 offers a selectable 3-pole, low-pass filter with a user-set cut-off frequency.
Up to 8 DBK16 boards can be connected to each of 16 analog LogBook or Daq device base channels for
a maximum of 256 input signals. Remote-sense terminals are used with 6-wire Kelvin connections.
The DBK16 provides an amplifier gain range of ×100 to ×12,500 for use with strain gages having 0.4 to
10 mV/V sensitivities. Most strain gages are specified for a full-scale value of weight, force, tension,
pressure, or deflection with an output of mV/V of excitation. For example, a strain gage with a full-scale
rating of 1000 lb of tension might output 2 mV/V of excitation at full load. With an excitation of 10 VDC,
1000 pounds of load would produce an output of 20 mV.
The card’s 0 to 5 VDC offset and output-scaling permit nulling of large quiescent (inactive or motionless)
loads and expansion of the dynamic range for maximum resolution. Typically, the quiescent output is non-
zero. Prior to a force being applied, a mounted strain gage can be in a state of partial deflection resulting in
an output. In the case of a tension gage, this output may be due to the weight of a hook or empty container.
DBK Option Cards and Module
879895
DBK16, pg. 1