The ESPEC EHS-221(M) hast test chamber with 355*355*426mm (W*D*L) 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) |
Hirayama Hast Chambers Models and Technical Parameters
When configuring a Highly Accelerated Stress Test (HAST) system for biased testing or electrochemical (ion) migration evaluation, the number of specimen signal terminals (pins) dictates how many samples you can test simultaneously. Because a complete electrical circuit for a single specimen typically requires two pins (positive and negative), understanding the maximum terminal capacity of your chosen equipment is critical for testing efficiency. To help our customers make the most informed decisions, we have compiled a comprehensive comparison of standard terminal capacities from leading HAST chamber manufacturers in the market.
| Standard Hirayama HAST models are generally equipped with 20 signal terminals. Depending on the specific chamber dimensions—such as the PC-304R8, PC-422R8, or the PC-R9 series—the wiring capacity can be expanded. Generally, smaller units can be upgraded to 60 terminals, while larger standard units max out at 80 to 100 terminals. | Terminal Configurations in Hirayama HAST Chambers |
| For highly specialized electrochemical migration evaluations, Hirayama offers a customized 128-pin long-life configuration as an optional upgrade. | |
| ESPEC HAST chambers offer a modular approach to specimen wiring. Their standard EHS series models include 12 pins per chamber as the baseline configuration. Depending on the testing requirements, these can be expanded in 12-pin increments up to a maximum of 72 pins for standard units. | Terminal Configurations in ESPEC HAST Chambers |
| To accommodate the growing demand for large printed circuit boards (PCBs) and high-volume batch testing, ESPEC introduced deeper and larger capacity models. The EHS-222M-L, for instance, features an expanded depth and supports high-voltage, multi-pin energized testing up to 120 pins. | |
| For users requiring even more substantial interior space for massive testing batches, ESPEC provides large-capacity units such as the EHS-432 and EHS-432M, which deliver up to 130 liters to 180 liters of internal volume to handle extensive specimen arrays. |
| Manufacturer / Brand | Equipment Type / Series | Standard Pins (Terminals) | Max Expandable Pins (Standard Range) | Max Pins (High-Capacity/Customized) |
|---|---|---|---|---|
| Hirayama | PC-304 Series | 20 Pins | Up to 60 Pins | 128 Pins (Specialized Ion Migration) |
| Hirayama | PC-422 Series | 20 Pins | Up to 80 – 100 Pins | 128 Pins (Specialized Ion Migration) |
| ESPEC | EHS-212 / 222 / 412 | 12 Pins | Up to 72 Pins | N/A |
| ESPEC | EHS-222M-L | 12 Pins | Up to 72 Pins | 120 Pins (High-voltage support) |
| Wewon Tech | Biased HAST System | 44 Pins | Customizable | Contact us for High-Density Customization |
Valuable Resources for ESPEC EHS-211 / EHS-211M Users
As a team dedicated to the research, development, and manufacturing of environmental test chambers, we always hold deep respect and appreciation for outstanding product designs in our industry. There is no doubt that ESPEC HAST chambers are remarkable representatives in this field.
To assist engineers and purchasing managers who are currently evaluating or already operating models like the EHS-211 and EHS-211M, we have curated two highly valuable reference documents for your convenience:
- • ESPEC EHS-211 & 211M User Manual: A comprehensive guide covering detailed operation instructions and daily maintenance for this series.
- • ESPEC EHS Series RS-485 Communication Function Guide: Specifically for users who need to integrate the chamber into their laboratory network, detailing the RS-485 communication function and system integration settings.
We hope these detailed manuals provide substantial convenience for your daily testing work. Whether you are looking for a reliable HAST testing solution or need customized terminal pin configurations for your bias testing, please feel free to reach out to our engineering team for support.
Looking for a High-Performance Alternative to ESPEC?
While ESPEC HAST chambers are widely recognized for their excellence, achieving the same rigorous testing standards doesn’t have to break your budget. As an original manufacturer, our Biased HAST & PCT Pressure Cooker Test System delivers equivalent performance to top-tier models like the Hirayama PC-422R8 and ESPEC series.
Automotive Reliability Testing: For the Automotive Electronics sector, this system is essential for validating components against rigorous AEC-Q100 standards, ensuring they can withstand the harsh temperature-humidity extremes found in modern vehicles. Our equipment is indispensable for evaluating moisture integrity, specifically analyzing mold compounds for delamination and lead frames for corrosion susceptibility.
Fully compliant with the JEDEC JESD22-A110 and IEC 60068-2-66 standards, our dual-mode environmental chamber is engineered to accelerate moisture penetration and precisely identify failure mechanisms such as ion migration and dielectric breakdown in non-hermetic packages.
Explore Our Alternative Solution →
Advanced Dual-Mode Testing: HAST & PCT Pressure Cooker Test
Unlike single-function autoclaves, the Wewon testing system offers versatile capabilities to cover the full spectrum of accelerated life testing. It features both Unsaturated Vapor Pressure (HAST) and Saturated Steam (PCT) modes.
The Biased HAST Mode meets the JEDEC JESD22-A110 requirements by allowing the application of electrical bias under controlled, non-condensing humidity. It is specifically designed to detect electrochemical migration (ECM) and dendritic growth between conductive paths, a critical failure mode in high-density ICs. For engineers adhering to established industry habits, the PCT (Pressure Cooker Test) mode delivers 100% RH saturation at elevated temperatures up to +142.9°C.
- ✔ Precision Control: Maintains humidity levels between 75% to 100% R.H. with a temperature range up to +162.2°C.
- ✔ Structural Upgrade: Built with SUS#316 electropolished stainless steel and features double-layer insulation to minimize surface heat loss.
- ✔ Ergonomic & Safe: A redesigned basket and sliding rack system ensures safe loading of complex PCBs, backed by redundant safety interlocks.
Whether you are evaluating automotive electronics (AEC-Q100) or semiconductor mold compounds, our Biased HAST System provides precise and reliable test data at a highly competitive factory-direct price.