TAM AIR ISOTHERMAL CALORIMETRY
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TAM AIR isothermal calorimetry Monitoring the thermal activity or heat flow of chemical, physical and biological processes provides information which cannot be generated with other techniques. Isothermal calorimetry is a powerful technique for studying heat production or consumption and is non-destructive and non-invasive to the sample. The TAM Air offers unmatched sensitivity and long-term temperature stability with flexible sample requirements. The TAM Air is the ideal tool for large scale calorimetric experiments, capable of measuring several samples simultaneously under isothermal...

tam air CEMENT AND CONCRETE HYDRATION A Powerful Tool for the Study of Cement and Concrete Hydration Processes Determining the heat of hydration of cement and concrete is important and traditionally the heat of hydration has been determined by measuring the heat of solution (ASTM C186). More recently, isothermal calorimetry tests using TAM Air are favored because they accurately and reliably measure the heat of hydration (ASTM C1702) and predict the setting behavior of various cement mixtures. The samples tested in the TAM Air are often paste samples, where the cement hydration process can...

Reliable, Robust, Versatile The 8-Channel Standard Volume TAM Air is ideal for homogenous paste samples while the 3-Channel Large Volume calorimeter can accommodate the more heterogenous concrete samples as well. The shape of the heat flow curve will reflect the cement hydration process and the different phases of the complex process can be determined. The addition of admixtures will change the shape of the heat flow curve and the admixture effect can be quantified. The integrated heat flow over time will give the extent of hydration. Using isothermal calorimetry, the heat of hydration is...

Performance Specifications 3-Channel 8-Channel Large Volume Standard Volume Calorimeter Calorimeter Thermostat Specifications Calorimeter Positions Short Term Noise Operating Temperature Range Thermostat Type Thermostat Stability Maximum Sample Size Calorimeter Specifications Baseline over 24 hours * Baseline drift specification is based on a 24-hour room temperature cycle and can be extended to be valid for multiple days and up to several weeks

Isothermal Calorimetry Calorimetry requires little or no sample pretreatment; solids, liquids and gases can all be analyzed. When heat is produced in a sample, isothermal calorimetry measures the heat flow. The sample is placed in an ampoule that is in contact with a heat flow sensor that is also in contact with a heat sink. When heat is produced or consumed by any process, a temperature gradient across the sensor is developed. This will generate a voltage, which is measured. The voltage is proportional to the heat flow across the sensor and to the rate of the process taking place in the...

High Performance Temperature Control and Stability The TAM Air is an air-based thermostat, utilizing a heat sink to conduct the heat away from the sample and effectively minimize outside temperature disturbances. The calorimeter channels are held together in a single removable block. This block is contained in a thermostat that uses circulating air and an advanced temperature regulating system to keep the temperature very stable within ±0.02 K. The high accuracy and stability of the thermostat makes the calorimeter well-suited for heat flow measurements over extended periods of time, e.g....

Calorimeters The TAM Air calorimeter block is available in two versions, both employing twin-type calorimeters. The 3-Channel Large Volume Calorimeter block has three twin-type calorimeters that can accommodate 3 samples of up to 125 mL volume. The 8-Channel Standard Volume Calorimeter can accommodate eight samples of up to 20 mL volume. In both calorimeter blocks, all the samples can be measured simultaneously and independently of each other. The only characteristic of each experiment in common is the thermostat temperature. The calorimeter blocks are interchangeable in the TAM Air...

TAM Air Ampoules The sample handling system for TAM Air includes static 20 mL and 125 mL ampoules, as well as a 20 mL Admix ampoule system. The ampoules available for use in the 8-Channel Calorimeter block accommodate sample sizes up to 20 mL volumes. Both glass and plastic (HDPE) closed ampoules are available. These ampoules enable maximum flexibility for sample management and sensitivity. The 3-Channel Large Volume Calorimeter block accommodates sample sizes of up to 125 mL. These 125 mL ampoules are available in both glass and stainless steel.

Admix Ampoule The Admix Ampoule is a 20 mL accessory available for the 8-Channel Standard Volume Calorimeter. It is used for initiating reactions inside the calorimeter, and can be used for monitoring a reaction from the initial injection. The Admix Ampoule can be configured with or without a motor for stirring. For samples such as mixtures of cement and water, manual stirring is recommended. For liquid systems, a motor may be used for stirring. The Admix Ampoule can only be used with 20 mL disposable glass ampoules. Admix Ampoule with manual stirring Admix Ampoule with stirring motor

Complexity of Cement Hydration Process The cement hydration process is temperature-dependent and mechanistically complex. Controlled studies at multiple temperatures provide setting profiles at each condition as well as insight into the multiple chemical reactions and their individual temperature dependencies. The directly measured output of a TAM Air measurement is the heat flow profile over time. A direct reflection of the rate of reaction, this is shown for three temperatures of the same system in Figure A. The integral of this heat flow over time, the Total Heat, is a measure of the...