The ESPEC EHS-221(M) hast test chamber with 355355426mm (WDL) test area and 0.1 ~ 0.4MPa pressure range which could meet our testing requirement. So we have ordered one piece ESPEC EHS-221M hast chamber for IC chips highly accelerated stress test work. In fact, There are many types ESPEC hast chambers on the market, We did a comparison of the different models of ESPEC hast chambers before we order this machine.
I have to say, This ESPEC EHS 221M hast chamber which we have ordered has a perfect structure design. So if you need a hast accelerated aging test chamber, Please don’t hesitate to buy this model. This article will much easier for you to understand each model of ESPEC hast chamber’s test room, pressure range and the testing performance difference.

According to the user manual of ESPEC hast test chamber, For the humidifying water, Please make sure that you will use pure water not less than 0.05MΩ.cm (20μS/ cm or lower). The temperature, humidity indication and control operations for ESPEC hast test chambers are based on the steam pressure table of table A.1, Annex A, IEC 60068-2-66 test standard.
Model Number | Interior Dimensions | Interior Volume | Temperature Range | Humidity Control | Pressure Ranges for Different ESPEC Hast Chambers Models |
EHS-212M | 11.5 x 11.6 x 11.5 | 0.64 cu. ft. | +105°C to +142°C | 75% to 100% RH | Pressure: 0.02 to 0.196 MPa gauge (0 to 28 psig) |
EHS-222M | 15.5 x 16 x 15.5 | 1.62 cu. ft. | +105°C to +142°C | 75% to 100% RH | Pressure: 0.02 to 0.196 MPa gauge (0 to 28 psig) |
EHS-212MD | 11.5 x 11.6 x 11.5 | 0.64 cu. ft. | +105°C to +142°C | 75% to 100% RH | Pressure: 0.02 to 0.196 MPa gauge (0 to 28 psig) . Two chambers in one unit. |
EHS-222MD | 15.5 x 16 x 15.5 | 1.62 cu. ft. | +105°C to +142°C | 75% to 100% RH | Pressure: 0.02 to 0.196 MPa gauge (0 to 28 psig) . Two chambers in one unit. |
EHS-412M | 11.5 x 11.6 x 11.5 | 0.64 cu. ft. | +105°C to +162°C | 75% to 100% RH | Pressure: 0.02 to 0.392 MPa gauge |
EHS-412MD | 11.5 x 11.6 x 11.5 | 0.64 cu. ft. | +105°C to +162°C | 75% to 100% RH | Pressure: 0.02 to 0.392 MPa gauge (0 to 57psig). Two chambers in one unit. |
EHS-431M | 22.0 x 22. x 22. | 4.00 cu. ft. | +105°C to +162°C | 75% to 100% RH | Pressure: 0.02 to 0.392 MPa gauge. Cylindrical workspace |

Model Description | EHS-211 (M) | EHS-211 MD | EHS-221 (M) | EHS-221 MD | EHS-411 (M) | EHS-411 MD |
Pressure Vessel Construction | Cr-Ni-Mo Stainless Steel Plate | |||||
Door Construction | Cr-Ni-Mo Stainless Steel Plate | |||||
Outer Shell Construction | Cold-rolled steel plate (SPC Class1) with melamine resin baked finish, FRP (Fiber reinforced plastics) resin | |||||
Insulation | Glass Wool for Different Model ESPEC Hast Chambers | |||||
Pressure Vessel Components | Temperature sensor (Thermocouple type T 〔Copper/Copper-Nickel〕 for measuring chamber temperature,humidifying water temperature, wet-bulb temperature), herter, specimen signal terminals, air-circulating fan, fan motor, overheat protector, boil-dry protector | |||||
Door | Auto-Locking Mechanism|Bank Vault | |||||
Test Area | Specimen shelves, shelf brackets for test area: Each×2 | |||||
Control Panel | Temperature, humidity, time displays, power ON/OFF key, setting keys, process lamps, alarm lamps, door lock/ release key | |||||
Water Supply System | Automatic water supply (Water supplied only at test start) Water supplied per start | |||||
Water Supply Amount | 1 Liter | 1.5 Liters | 1 Liter | |||
Other | Exhaust valve, air supply valve, deain filter, drain valve, air injection pump, water supply pump, water supply valve | |||||
Components | Temperature and humidity controller, Specimen signal terminals, Communication function (RS-485), Power cable | |||||
Pressure Gauge | Scale: -0.1 to 0.4MPa (Gauge) | Scale: -0.1 to 1MPa (Gauge) | ||||
Loading Capacity | 18L | 18L×2 | 46L | 46L×2 | 18L | 18L×2 |
Test Area Dimensions(mm) | W255×H255×L318|W10×H10×L12.5 inch | W355×H355×L426|W14×H14×L16.8 inch | W255×H255×L318|W10×H10×L12.5 inch | |||
Outer Dimensions (mm) | W640×H1483×D850 (W25.2×H58.9×L33.5 inch) | W760×H1795×D1000 (W29.9×H70.7×L39.4 inch) | W740×H1553×D1000 (W29.1×H61.1×L39.4 inch) | W860×H1795×D1000 (W33.9×H70.7×L39.4 inch) | W640×H1483×D850 (W25.2×H58.4×L33.5 inch) | W760×H1795×D1000 (W29.9×H70.7×L39.4 inch) |
Gross Weight | Approx 190kg | Approx 350kg | Approx 230kg | Approx 390kg | Approx 190kg | Approx 350kg |
Transport Space (mm) | W690×H1540 (W25.2×H21.3 inch) | W810×H1850 (W31.9×H72.8 inch) | W790×H1610 (W31.1×H63.4 inch) | W910×H1850 (W35.8×H72.8 inch) | W690×H1540 (W25.2×H21.3 inch) | W810×H1850 (W31.9×H72.8 inch) |