4K 0.5 W Closed Cycle Optical Cryostat
| Model | REF-4K-0.5W | REF-4K-0.5W-20 |
| Compressor | CNA-11C (Air Cooled) CJW-21A (Water Cooled) | CNA-31C (Air Cooled) |
| Cooling capacity | 0.5W@4.2K 3/4W@50K (1st stage) |
0.5W@4.2K 15/20W@40K (1st stage) |
| Lowest Temperature (zero heat load) |
<3.5K | <3.5K |
| Power Requirement | 200v AC 3-phase 2.7kW@60Hz 3.5kW@50Hz |
3.8/4.5kW |
| Weight (cold head) |
14kg | 16kg |
| Weight (compressor) |
70kg | 95kg |
| Std. flex hose length | 10m | 6m |
| 10,000 hours | 10,000 hours |
Model REF-1771-4K Variable Temperature Optical Closed Cycle Cryogenic Refrigerator System:
 | 4 to 325K operating temperature range |
| Two stage GM (Gifford-McMahon) coldhead |
| Air or Water Cooled compressor (AC 200v 3 phase) |
| Cooling power: 0.50 watt at 4.2K |
| 10 m interconnecting hoses and control cable |
| Initial cooldown time: approx. 90 minutes to 4.2KSubsequent cooldown time: <45 minutes |
|
3/4 watts at 50K (50/60 Hz), 15/20W at 40K optional |
| (4) 1.00 inch diameter clear optical quartz windows |
| Demountable optical first-stage radiation shield |
| Quick Release optical outer vacuum shroud |
| 55 mm diameter refrigerator sample mount |
| 50 ohm high power heater installed on coldhead |
| 19-pin electrical feedthrough with mate |
| (2) Spare blank feedthrough ports |
| Reliable bellows style evacuation valve |
| Vacuum shroud safety pressure relief |
| Adjustable Position Mounting flange - rotational and vertical adjustment |
| (2) matching silicon diode temperature sensors - installed on cold finger and sample holder |
| Optical and resistivity sample holders |
| 24 bits A to D Autotune PID Temperature Controller |
| Start-up toolkit with operational manuals |