The Yamato FO-311CR is a 7.5 L benchtop muffle furnace reaching 1150 °C with ±2 °C control accuracy at top temperature, on a low-mass ceramic-fiber chamber with a factory-fitted communication port for RS485/RS232C data output. It is the 220 V single-phase build of the 7.5 L FO furnace, documented in the manual as model FO310. The 115 V sibling is the FO-301CR.
Key Specifications
| Model / capacity | Yamato FO310 (FO-311CR, comm-port gen): approx. 7.5 L |
| Operating temperature range | 100 to 1150 °C |
| Adjustment accuracy | ±2 °C (at 1150 °C) |
| Time to reach temperature | Approx. 70 min to 1150 °C (approx. 50 min to 850 °C) |
| Control system | PID control by VS4 controller |
| Sensor | R thermocouple (W sensor) |
| Setting / display | Digital setting; digital display |
| Operation functions | Fixed temperature; timer (auto-stop, auto-start); program (max. 6 patterns; 30 steps×1 / 15×2 / 10×3) |
| Communication | Communication port (RS485/RS232C): CR generation |
| Additional functions | Lock function; auto recovery after power failure; calibration offset |
| Heater | Iron-chrome wire (Kanthal AF), 2.0 kW |
| Furnace unit | Ceramic fiber |
| Cooling fan | Axial fan motor |
| Safety devices | Earth-leakage/circuit breaker, thermal fuse, overheating-prevention device, self-diagnostics |
| Ambient temperature range | 5 to 35 °C |
| Internal dimensions | 200 × 250 × 150 mm (W×D×H) |
| External dimensions | 446 × 505 × 566 mm (W×D×H) |
| Weight | Approx. 37 kg |
| Power supply | 220V AC single phase, 50/60 Hz (base FO310: 200V, 11 A) |
Application Profile
A muffle furnace isolates the sample from the heating elements behind a refractory "muffle," so combustion products and radiant elements never contact the charge. The reason it is the standard tool for gravimetric ashing, loss-on-ignition, sample incineration, and heat treatment. Reaching 1150 °C, the FO-311CR covers ASTM/AOAC ash determinations, coal and food ashing, and residue-on-ignition work, where a clean, repeatable burn-off makes the mass measurement valid. Its 7.5 L chamber batches a full crucible tray per run; the 220 V single-phase supply draws a lower line current (11 A) than the 115 V FO-301CR (21 A) for the same 2.0 kW heater.
The ceramic-fiber chamber heats and cools quickly and draws less power than a firebrick furnace, reaching 1150 °C in about 70 minutes. Control is PID via the VS4 controller with an R thermocouple, holding ±2 °C at 1150 °C; a 6-pattern program (up to 30 steps) scripts staged ramp-soak-cool profiles for reproducible ashing or annealing. For clean gravimetry, allow full burn-off before weighing and (where volatile or corrosive off-gassing is expected) add the optional exhaust system unit.
Frequently Asked Questions
What maximum temperature does the FO-311CR reach? It operates from 100 to 1150 °C, with ±2 °C adjustment accuracy at 1150 °C.
What is the electrical supply? It is a 220 V AC single-phase unit drawing 11 A (documented base model FO310), half the line current of the 115 V FO-301CR at 21 A, for the same 2.0 kW heater.
How long does it take to heat up? Approximately 70 minutes to reach 1150 °C (about 50 minutes to 850 °C).
What does the "communication port" (CR) add? The CR generation provides an RS485/RS232C communication port for data output/logging.
Can it run automated ramp-and-soak profiles? Yes. The VS4 controller supports fixed-temperature, timer, and program operation with up to 6 patterns, plus auto-recovery after a power failure.
Ordering & Configuration
Add to quote or cart for a formal quotation. At quote we confirm supply voltage (this is the 220V SKU; order FO-301CR for 115 V), exhaust/off-gas handling, any output-terminal or sample-tray options, and lead time.
At ~37 kg and 446 × 505 × 566 mm, site it on a stable, noncombustible bench with clearance and ventilation for the hot exterior and exhaust. Warranty: per Yamato standard capital-equipment terms, confirmed at quote.
Yamato FO muffle furnace, 7.5 L (comm-port generation):
- FO-311CR (this product): 7.5 L, 220V single phase
- FO-301CR: 7.5 L, 115V
- Step up to FO-411CR (9 L) or FO-511CR (11.3 L) for larger charges; step to the FP series for ±1.5 °C accuracy.
