MODEL 665 COMBO STRAIN GAGE AMPLIFIER MODULE
Description
The Model 665 is a combination computer-controlled static/dynamic strain gage amplifier module. Features include an adjustable gain, zero, external cal, filter, excitation and excitation monitor. Each channel has its own isolated constant current excitation source.
Specifications
| Amplifier channels: | Channel A is AC or DC coupled with variable gain and filter Channel B is DC coupled with two gains and fixed filter |
| Channel A gain settings: | Fixed log steps 1, 2, 5,10, 20, 50, 100, 200, 500, 1000, 2000, 5000 |
| Channel B gain settings: | 1 or 100 |
| Gain accuracy: | ±1% |
| AC/DC coupling: | Selectable on Channel A only |
| DC offset: | Rack control performs auto-zero at each gain or filter change; programmable offset from -100mVDC to +100mVDC; offset affects Channel A if DC coupled, else Channel B |
| Frequency response: | AC channel: Six-pole Butterworth lowpass, selectable at 5kHz, 20kHz, 40kHz or bypassed; 5Hz highpass, single pole DC channel: Four-pole Butterworth lowpass at 11Hz |
| Bridge mode: | ¼ bridge, ¼ bridge three-wire, ½ bridge, or full bridge with 120? and 350? internal completion resistors; EMF mode disconnects completion, balance, and excitation |
| Excitation: | Excitation source isolated from amplifier output common; constant voltage, programmable from 1.0-15.0VDC; up to 100mA available; short-circuit current limited to under 40mA |
| Bridge balance: | Autobalance cycle initiated from control webpage; dual 12-bit DACs apply balancing current to +S leg of bridge; balances on channel A if DC coupled, else channel B |
| Fault indication: | One green LED per channel turns red if amplifier exceeds ±10V; both LEDs turn red if bridge autobalance cannot be completed |
| Offset: | Less than 3mVDC at output |
| Shunt calibration: | One of four precision cal resistors applied from -P to –S 11.88k, 19.88k, 49.00k, 99.00k |
| Noise: | Less than 5µ VRMS RTI, filter in, input disconnected |
| Memory: | On-board EEProm stores serial number, calibration date, etc. |
| Mechanical: | 5.5” x 13.5” board, use with Model 5020-102 rack |