TAFTS instrument specifications
| Parameter | Value |
|---|---|
| Interferometer | Martin-Puplet, differential inputs and outputs |
| Spectral Coverage | 800 cm-1 to 80 cm-1 in two bands (a) 800 cm-1 to 330 cm-1 and (b) 330 cm-1 to 80 cm-1 |
| Filtration | Dichroic filters to match detector responses |
| Resolution | 0.1 cm-1 |
| Optical path | 100 mm (total OPD, for D/S interferograms) differential scan, four-fold gearing |
| Scan drive | micro-stepping motor with pulley gearing system |
| Mirror carriage | Kinematic: precision V-grooves, 3 ball bearings |
| Acceptance solid angle | 6.28 x 10-4 steradians |
| Working Aperture dia. | 25 mm (Area = 4.91 x 10-4 m2) |
| Beamsplitters | 2µ |
| Optical System | Reflective, cooled field and aperture stops |
| Outputs | One pair differential outputs / spectral band |
| Detectors | Two pairs of photoconductors cooled to 4K probably (a) Silicon BIB and (b) Ge:Ga |
| Scan time | 2 S active, 2.5 seconds total |
| Optical path velocity | 50 mm per second |
| Mirror velocity | 25 mm per second |
| Fringe frequency bands | 5000 Hz -- 1500 Hz and 2500 Hz -- 400 Hz |
| ADC Sampling rate | fixed frequency 20 kHz / 10 kHz |
| Position measurement | HeNe interferometer |
| Sample correction | off-line digital filtering + phase correction |
| Sampling interval | 2.5µ |
| Total signal samples | 120,000 per scan (360,000 Bytes) |
| Laser timings | 40,000 samples precise to 1 in 1024 or 2048 |
| Total bytes per scan | 440,000 over 2.5 secs. |
| ADCs | 2 off Sigma-Delta 20 bit (Crystal CS 5390) |
| Data Rate (averaged) | 172 kBytes / second (= 604 MByte / hour, 4.82 Gbyte / 8 hours) |
| Recording Medium | 2 SCUSI Harddisk; 3.2G capacity each |
| Calibration | Four on-board black body sources |
| Instrument Controllers | Pentium PC, on-board 486 DX4/100 PC |
| Mass | 80 kg (Interferometer) 27 kg (control box) 3 kg (disk box) |
| Environmental | Down to -50 Centigrade, 50,000 feet Interferometer at ambient temp, evacuated some electronics at 10C, 1 atmosphere |
| Power Consumption | 200 Watts + heaters (Up to 1 kW) |