Model 10A73-4 Four Channel DC Strain Gage Conditioner
Intended primarily for stress analysis applications, the Model 10A73-4 receives and conditions up to four independent inputs from one-arm (1/4-bridge), two-arm (1/2- bridge), and four-arm (full-bridge) strain gage configurations attached directly to the stressed material. If you are measuring strain by means of a one-arm (1/4-bridge) strain gage configuration, BE SURE TO STUDY SECTION 4 FOR A DISCUSSION OF “LEAD WIRE AND NONLINEARITY EFFECTS WITH QUARTER-BRIDGE STRAIN GAGE CONFIGURATION.” Unless all four inputs originate from full-bridge transducers, the 10A73-4 requires external completion of each strain gage input to full bridge, by means of one of the following:
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a System 10 Bridge Completion Connector—one of the following models:
- 10QBC-4-120 for 2- or 3-wire 120-Ω quarter-bridge connections
- 10QBC-4-350 for 2- or 3-wire 350-Ω quarter-bridge connections
- 10QBC-4-1K for 2- or 3-wire 1000-Ω quarter-bridge connections
- 10HBC-4 for 4- or 6-wire half-bridge connections
- 10FBC-4 for 5-wire full-bridge connections
- a Daytronic Model 10CJB-4 Quad Bridge Completion Card or an equivalent circuitry supplied by the user
When the 10A73-4 is used with one of the System 10 Bridge Completion Connectors listed above, the excitation level is fixed at 5 V-DC. In the absence of a Bridge Completion Connector—whether or not the Model 10CJB-4 is used—the 10A73-4 provides selectable low-level excitation (1, 2, or 5 V-DC) to help reduce gage heating effects in materials with low thermal conductivity. However, the selection of excitation level for the 10A73-4 is not “per channel”; the same level applies to all four 10A73-4 channels. The 10A73-4 can be quickly calibrated either through “calculated” calibration—involving application of the MVV command—or through a convenient shunt technique. Unless a System 10 Bridge Completion Connector is being used with the 10A73-4, all four shunt resistors may be switched in and out simultaneously by means of logic-level inputs through the rear I/O connector.