A liquid helium level measurement solution using a superconducting filament as the sensing element. Meter and probe are supplied as one set, with an optional pulsed-current mode that reduces the helium loss caused by measurement. Suitable for superconducting magnets, particle accelerators, cryostats and liquid helium dewars.
Level measurement itself introduces heat into the liquid helium and causes evaporative loss. The pulsed-current mode lowers the average heating power while preserving accuracy, and so reduces the helium lost to measurement.
The probe is wired in a four-wire configuration with 28 AWG copper leads, removing lead resistance by principle; combined with resistance measurement better than 0.1% in the meter, this yields a stable, repeatable level reading.
The G10 outer tube is only 5.8 mm across, matching a wide range of liquid helium dewars and cryostats. Effective lengths of 200 / 400 mm and custom lengths are available.
Measures liquid helium level with an ultra-fine superconducting filament. Two independent display channels and a pulsed-current measurement mode that reduces helium loss.
G10 outer tube in a slim 5.8 mm design, matching a wide range of liquid helium dewars and cryostats. Custom lengths available.
Meter and probe are supplied as a set and must be purchased together. The values below are nominal factory figures; refer to the document supplied with the unit for actual parameters.
| Display channels | 2, independently displayed |
|---|---|
| Output current | 10–100 mA continuously adjustable; control accuracy better than 1 mA |
| Measurement accuracy | 0.1% (filament resistance measurement better than 0.1%) |
| Displayed information | Page height and helium inventory (one-touch toggle) |
| Display size / resolution | 4.3" / 800×480 |
| Measurement mode | Pulsed current mode |
| Alarm function | Low-level alarm, can trigger an external alarm device |
| Interfaces | RS-232, Ethernet, AUX I/O, DB9 level probe connector |
| Mains input | 100–240 Vac / 50–60 Hz, max input power 200 W |
| Communication | TCP server mode, fixed local listening port 8080 |
| Dimensions | 430 × 300 × 88.9 mm (2U chassis height) |
| Effective length | 200 mm / 400 mm / custom |
|---|---|
| Overall length | Effective length + 3 mm (3 mm clearance below) |
| Outer tube material | G10 |
| Outer tube diameter | 5.8 mm |
| Excitation current | 75 mA (recommended, configurable) |
| Voltage | 40 V |
| Leads | Four-wire, 28 AWG copper |
| Resistivity | 80.9 Ω/m @20 K 97.5 Ω/m @300 K |
| Liquid helium temperature range | 4.2 K ± 0.2 K |
| Nominal initial resistance | 32.7 Ω (CRYO-4K-200; recommended 90 mA / 3 s preheat) |
Level monitoring for a single liquid helium dewar. The meter's second channel can be left spare for a future second dewar or a backup probe.
Simultaneous monitoring of two independent vessels in the same system (for example a magnet dewar and a cold box), displayed side by side on one panel.
Connect over Ethernet or RS-232 to a laboratory control system. The meter runs as a local TCP server for unified logging and alarm interlocking.
Send us your dewar inner dimensions and mounting interface, and we will recommend the probe length and excitation current.
