YSM 540 Moisture-proof Cabinet 540L (YSM540A / YSM540B / YSM540C)

The YSM series spans 1–60% RH across its three grades: A holds 20–60% RH, B holds 10–20% RH and C holds 1–10% RH. Every grade is available across the full capacity range, so a 100 L bench unit and a 1430 L production cabinet can be specified to the same humidity window. Control accuracy is ≤ ±3% RH, and the display covers 0–99% RH. Temperature is displayed over −9 to 99 °C to ±1 °C but is not actively controlled — these are humidity cabinets.

Calibration intervals are normally set by your own quality system rather than by the cabinet: an ISO 9001 or customer-audited process usually defines how often instruments must be verified. A common starting point is annual verification against a reference, adjusted to whatever your audit actually requires. Tell us your calibration requirement when ordering and we will confirm what documentation accompanies the unit.

The specified accuracy is ≤ ±3% RH, with a display range of 0–99% RH. That figure describes the spread around the setpoint once the cabinet has stabilised, not the pull-down time. Real-world stability depends on how often the door is opened, the load inside, and the ambient conditions in the room. Cabinets used continuously with the door open are better served by the optional fast-purge configuration, which we can quote.

The F suffix denotes the anti-static build. In the standard model the cabinet is finished in ivory white; the F version uses a blue-grey finish and holds surface resistivity between 10⁶ and 10⁹ Ω, with a 1 MΩ earth lead fitted as standard. Everything else is shared: the same door lock, 5 mm tempered glass window, cold-rolled steel body, LCD display, sensor and dehumidifier. The F build is what you specify when handling ESD-sensitive components, where a static discharge would do the damage that the humidity control is preventing.

The cabinets auto-sense mains voltage and accept AC 110 V or 220 V at 50 or 60 Hz, so the same unit works on either supply without a step-down transformer or an internal change. Power draw is modest and depends on capacity and grade — a 100 L grade A cabinet draws 10 W, while the largest 1430 L grade C cabinet draws 78 W. The figure for each model is listed in the specification table. The ovens are different: models up to 240 L run on single-phase AC 220 V, and from 420 L upward on three-phase AC 380 V.

Shelf load ratings rise with cabinet size: 20 kg per shelf at 100–160 L, 30 kg at 240 L, 40 kg at 320 L, 50 kg at 450–730 L, 60 kg at 880 L and 100 kg at 1430 L. The number of shelves also increases with capacity — from one shelf in the 100 L models to five in the 730 L and larger units, giving up to six storage tiers. If your load is denser than the standard rating, tell us the weight and we will confirm what the frame can take or specify reinforcement.