DVS Resolution

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Description

Surface Measurement Systems

The world’s most advanced DVS Instrument, DVS Resolution is a dual vapor gravimetric analyser, with key feature, is the combined ability to precisely control and measure temperature and relative humidity while recording the highest resolution changes in mass. DVS Resolution uses a dry carrier gas typically nitrogen or compressed air for its operation. Digital mass flow controllers regulate flows of dry and saturated gases.

Relative humidity is generated by precisely mixing dry and saturated gas flows in desired flow ratios which produce expected relative humidity. In a typical experiment a known concentration of water vapor is delivered over a sample placed inside the sample pan connected to the Surface Measurement Systems UltraBalance™ measuring realtime mass changes caused by sorption or desorption of water molecules. Prior to sorption measurements, the sample can be in-situ preheated/dried at temperatures of up to 200 oC.

Additionally, the sample chamber and water vapor generation are at thermal equilibrium in a single temperature enclosure allowing for operation over the entire temperature range (5-85°C) without risk of condensation.

Key Differences

Outstanding performance

Long Term Temperature Stability

• Vapor generation and delivery at sample temperature

• Typical stability at 25 °C is ±0.02 °C

• Prevents condensation issues found in instruments with multiple temperature zones

• Allows for accurate and stable humidity delivery

Humidity Performance

• ±0.1% RH of target humidity

• Highest level of humidity precision in any instrument we’ve ever produced

Balance Baseline Stability over 24 hours

• Mass changes at a resolution of 0.1 μg

• Root mean square noise of ≤ 0.3 μg

True0™ RH

• Only DVS instrument offering True0™ RH

• Achieve partial pressures of water as low as 0.0% RH

• Study of hydrates and other compounds only completely dry below 1% RH

• Allows investigation of sorption/desorption at low RH levels

Key measuring capabilities:

• Water, organic solvent, and gas sorption and desorption isotherms

• Co-adsorption isotherms using two vapors

• Optional in-situ sample preheating/drying to 200 °C

• Multiple sorption/desorption and sample drying or activation cycles

• Sample masses from 1 mg to 5000 mg

• Surface and bulk measurement capabilities and analyses

Key hardware benefits:

• Only system to measure organic vapor partial pressure directly using Ultrasonic Sensor (patent pending)

• Open stainless steel stand design enabling easy access to sample pan while minimizing static electric charging

• Broad range (5-85 °C) and single uniform and accurate temperature enclosure

• Next generation control and evaluation software for the most advanced experimental design and data analysis

• Capable of upgrading to 5 balances

• Optional IR, Raman and Video imaging with integrated control software

Technical Specification

Temperature

Temperature controlled enclosure
Control range: 5 °C to 85 °C
Control precision: ±0.1°C
Enclosure also provides anti-condensation protection

High temperature pre-heater for sample drying/activation

Delivers local sample temperatures of up to 200 °C
Heating ramp rates: up to 10 °C / min
Sensor: Pt-100 thermocouple

Resolution Stand

Manifold: 316 stainless steel
Seals: Viton
Tubing: 1/4 inch stainless steel

Solvent Reservoirs

Material: Pyrex glass
0.25 and 0.5L as standard
2 Reservoirs included

Relative humidity generation and measurement

High accurate digital mass flow controllers and capacitance probe

Relative Humidity Sensors

Capacitance probe

Carrier Gas – Dry air or Nitrogen
Relative humidity range from 0 to 98%
RH range accuracy from 5 – 60 °C ±1%
RH range accuracy from 60 – 85 °C ±2%

Speed of Sound Sensor for organic vapors

Carrier Gas – Dry air or Nitrogen
Partial Pressure range from 0 to 90%
Partial Pressure accuracy from 10 – 70 °C ±1%

Solvents Available include:

Acetone
Chloroform
Cyclohexane
Decane
Dichloromethane
Dichloromethane
Ethanol
Ethayl acetate
Ethyl benzene
Heptane
Hexane
Isopropanol
Methanol
Nonane
Octane
Toluene
Water
M-Xylene
p-Xylene

System Software

Next generation purpose built control and evaluation software for the
most advanced experimental design and data analysis.

DVS Control

Complex protocols for multiple experimental sequences using sample pre-heating and conditioning; isotherm, isobar and ramped humidity and organic vapor methods; single or dual vapor delivery and control; fixed time or mass derivative steps.

Multiple-method protocols incorporating:
• Sample pre-heating
• Vapor sorption
• Vapor exchange
• Dual vapor co-adsorption
• Temperature changes in a single experiment, including
• Ramp or step changes in relative humidity
• Automated video image acquisition
• Organic vapor sorption partial pressure
• Temperature stages may be based on fixed-time or user defined dm/dt criteria
• Complex isotherm experiments
• Experiments may include half, full or multiple partial pressure or temperature cycles

Analysis
• Isotherms
• Permeability and diffusion
• Kinetics information
• Heat of sorption
• Tg determinations
• Amorphous content
• BET

21CFR Part 11 software solution is available for all DVS software upon request.

Mass measurement

UltraBalance™ low mass
Sample mass: between 1 and 1000mg
Mass change: ±150mg
Resolution (precision): 0.1 μg
Root mean square
balance noise: ≤ 0.3 μg

UltraBalance™ high mass
Sample mass: between 10 and 5000mg
Mass change: ±1000mg
Resolution (precision): 1 μg
Root mean square
balance noise: ≤ 3 μg

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