High-concentration water vapor atmosphere STA (TG-DSC)
A thermal analysis system for easy TG-DSC measurements in a water vapor atmosphere
STAvesta/HUM-Auto combines a thermogravimetric-differential scanning calorimeter with a water vapor generation system to perform TG-DSC measurements in a controlled water vapor atmosphere. By connecting to HUM-Auto, which allows switching between relative humidity control and dew point control, the system automatically controls each temperature according to the set humidity and also supports humidity control synchronized with the temperature program.
STAvesta/HUM-Auto Overview
For details on the basic performance of STAvesta, please refer to the main STAvesta page.
STAvesta/HUM-Auto is a system that enables TG-DSC measurements under humidity-controlled conditions by connecting a water vapor generation unit to the STA. Its indirectly heated electric furnace designed for the introduction of water vapor and temperature-controlled structure help suppress condensation while creating a stable humidity atmosphere. This makes it possible to evaluate the effects of humidity conditions on sample mass changes and thermal behavior.
HUM-Auto automatically controls the water bath temperature, transfer tube temperature, and circulator temperature according to the set humidity. Users can switch between relative humidity control and dew point control, and the system also supports humidity control synchronized with the temperature program. Because it can be connected to a gas cylinder or similar supply without requiring special utilities, it is easy to introduce into existing measurement environments.
By connecting an automatic sample changer, the system also supports continuous measurements, helping improve measurement efficiency under humidity-controlled conditions.
Like other STA models, the furnace unit is interchangeable with six different types of furnaces, offering wide applicability for various measurement needs.
STAvesta/HUM-Auto Features
STAvesta/HUM-Auto Specifications
| Model name | Thermo plus EVO3 STAvesta/HUM-Auto | |
|---|---|---|
| Instrument name | High-concentration water vapor atmosphere thermogravimetric-differential scanning calorimeter | |
| Balance type | Horizontal differential thermobalance (TG-DSC) | |
| Measurement temperature range | Room temperature to 1400°C | |
| Heating rate (max) | 20°C/min | |
| Sample amount (max) | 1 g (90 μL) | |
| TG range | ± 500 mg | |
| DSC range | ± 600 mW (100°C) ± 1400 mW (1000°C) |
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| DTA range | ± 1000 μV | |
| Humidity control range | Room temperature to 80°C, 5 to 90%RH | |
| Wet gas flow rate | 200 to 600 mL/min | |
| Transfer tube temperature | Max. 110°C | |
| Water bath temperature | Room temperature to 90°C | |
| Dry gas flow rate | HUM-Auto: 200 to 500 mL/min Balance purge gas: 150 mL/min |
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| Stabilization time after humidity change | Within 10 min (10%RH) | |
| Continuous operation time | 60°C 90 %RH, more than 100 hrs 80°C 90 %RH, more than 40 hrs |
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| Variable humidity system | Feedback type humidity control system | |
| Temperature and humidity sensor | Humidity sensor: Polymer-type relative humidity sensor Temperature sensor: Platinum resistance thermometer Calibration accuracy (humidity): ±1.5 %RH (10 to 95 %RH at 25°C) Calibration accuracy (temperature): ±0.3°C |
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| Mass flow controller (built-in) | One unit each for dry gas and wet gas (water bath bubbling gas) | |
| Controlled humidity system | PID control | |
| Humidity stability | ± 2 %RH after reaching the set value | |
| Gas type | Dry N₂ gas | |
| Bubbler volume | 300 mL | |
| Measurement atmosphere | Humid atmosphere | |
| Options | Automatic sampler changer (samples: 52, references: 3, calibration samples: 5) | |
| Dimensions | STAvesta 412(W) x 355(H) x 621(D) mm 412(W) x 705(H) x 621(D) mm with ASC HUM-Auto 200(W) x 250(H) x 420(D) mm |
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| Mass | STAvesta 50 kg 66 kg (with ASC and safety cover) HUM-Auto 7 kg |
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| Power requirements | STAvesta 1Ø, AC100-120V/200-240V, 50/60Hz, 15A HUM-Auto 1Ø, AC100-120V/200-240V, 50/60Hz, 6A |
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