Sorbent Tube Conditioning Rig

Content
1. What is sorbent tube conditioning rig?
    1.1 Feature of sorbent tube conditioning rig
    1.2 Technical parameters of sorbent tube conditioning rig
2. Why use sorbent tube conditioning rig?
    2.1 Why do we need to age thermal desorption tubes?
    2.2 Why is it not recommended to use a thermal desorption unit to age sorbent tubes?
3. Use of sorbent tube conditioning rig
4. Precautions for using sorbent tube conditioning rig
    4.1 The background of the sorbent tube conditioning rig affects the background of the resolving tube
    4.2 The effect of the sorbent tube conditioning rig on the service life of the analysis tube
    4.3 The importance of sorbent tube conditioning rig temperature and flow control
5. How to buy sorbent tube conditioning rig?

Sorbent tube conditioning rig is designed to improve the working efficiency of the testing supporting parts on the basis of a thermal desorption instrument. It can complete the activation process of 1-10 adsorption tubes independently without connecting any other temperature control equipment because there is an independent temperature control system. It comes with a flow meter and displaying intuitive and easy to operate. It can be used in environmental monitoring, occupational health, quality inspection institute, immigration, building science institutes, metrology institutes, universities and scientific research institutions, third-party testing and automobile testing industry, etc.

a. Aging 10 adsorption tubes at one time, and the number of aging arbitrary adjustment to facilitate the use of users.

b. With a temperature control system, no need for any other external temperature control equipment. Precise and stable temperature control.

c. 6-step programmed temperature control, which can meet some special application requirements.

d. Integrated design of temperature control and timing control, simplifying operation.

e. With aging end buzzer reminder function.

f. Adopt built-in gas flow meter to facilitate the adjustment of flow rate.

g. Adopt secondary pressure control to avoid the influence of gas source pressure fluctuation on the flow rate.

h. Heat preservation and heat dissipation design, the instrument will not overheat on the outer surface during long time operation.

Thermal desorption tubes need to be aged, whether they are used for the first time or are being reused. The reason for this is that organic residues are left behind in the synthesis of new desorption tube packing and are not completely removed. There are also traces of organic residues on the empty tubes, fittings, and glass wool filled inside the tubes. The reused desorption tube may bring in some semi-volatile or non-volatile impurities when sampling. At the same time, if the thermal analysis tube is not sealed properly during storage and transportation, it may also adsorb volatile organic compounds in the environment, causing the background of the thermal analysis tube to increase. Therefore, before using the thermal analysis tube, the tube needs to be fully aged with an aging device.

For the new thermal desorption tube, it needs to be aged for 1-2 hours at the specified aging temperature. For thermal desorption tubes that are already in repeated use, they only need to be aged at the specified temperature for about 20 minutes.

Most thermal desorption units have the function of aging the sorbent tube. The reason for not recommending users to use the thermal analyzer to age the tubes is that using the thermal analyzer for aging will increase the costs.

When using thermal desorption unit, only one thermal desorption tube can be aged at a time, so the aging efficiency is very low. The use of a sorbent tube conditioning rig can age several analysis tubes at the same time, greatly improving the efficiency of the experiment.

The use of thermal analysis instruments for aging greatly reduces the service life of many of the internal sealing components of the thermal analyzer, resulting in air leakage from the thermal analysis system, instrument error reporting, and ultimately, failure of the sample to function properly. In this case, the internal parts of the instrument, mainly the O-rings, need to be replaced, and the material cost is high. In addition, there are some parts of the O-ring that users cannot replace by themselves and require instrument engineers to visit the instrument for maintenance, which greatly increases maintenance costs.

As shown in the figure above, the structure of a typical thermal analyzer gas circuit has O-rings at 1, 2 and 3 to seal the joints. The O-ring is a perfluorinated O-ring with high-temperature resistance and ultra-low loss. However, the O-ring has a service life. As the heat time increases, the material inside the O-ring will continue to be lost, resulting in a decrease in the sealability and a failure of the system self-test. For example, in the conventional thermal analysis process, the heating time of a single system is only 3-10 minutes. If a thermal analyzer is used to analyze the aging of the tube, the single system heating time will be extended to 30-120 minutes. The extended system heating time can significantly reduce the service life of the O-ring. The forced need for O-ring replacement and maintenance greatly increases time and financial costs. Therefore, it is not recommended to use a thermal resolver to age the resolver tube, and it is recommended to use a sorbent tube conditioning rig to complete the work of aging the resolver tube.

a. Connect the "air inlet" to the nitrogen gas before using the instrument, and make sure there is no air leakage from the connector.

b. Connect the "air outlet" of the instrument to the outdoor pipeline.

c. Inserting the power cord into the power supply slot.

d. Insert the heating plug into the heating slot.

e. Open the shut-off valve and adjust the needle valve to bring the flow rate to the desired value.

a. Set the time.

b. Start.

c. After aging is complete, place the adsorption tube on the front support of the heating box to cool before removing it. Turn off the power supply and cut-off valve.

The pre-treatment sampling process of thermal analysis is actually a sample enrichment process. The organic material is continuously enriched and concentrated in the packing of the analysis tube by the carrier gas. The sensitivity of the method and the detection limit of the sample is also greatly increased. Therefore, the sorbent tube conditioning rig also needs to strictly control the background loss of the instrument itself, so as to ensure that the organic background of the analyzer tube meets the method requirements. If the background of the aging system is high during the aging process, the background of the analyzer tube will have an impact on the sample results.

The adsorption efficiency of the thermal desorption tubes is determined by the packing inside, which has been degraded and lost under the repeated action of high temperature. When the loss reaches a certain level, the adsorption and desorption efficiency of the packing cannot guarantee the stability of the data. The presence or absence of carrier gas and the accuracy of temperature control during aging directly affect the degree and speed of packing loss, thus affecting the service life of the thermal analysis tube.

Generally, the service life of a thermal desorption tube is about 100 thermal cycles, and the use of a high-performance aging instrument can improve the service life of a thermal analysis tube.

Because of the variability of each desorption tube, it is very important that the temperature and flow rate of the aging instrument be controlled independently and precisely.

Due to the inhomogeneity of the packing, the back pressure of the resolving tube will vary from root to root, where the difference in the back pressure of the multi-layer packing will be even greater. In this case, if a single gas circuit is used to control the aging of multiple thermal analysis tubes, the tube with high back pressure will pass little or no carrier gas, resulting in dry burning of the tube and damage to the packing.

Aging temperature and gas flow rate are the two most important parameters for aging of the analysis tube. If the aging temperature is too low, the impurities in the packing cannot be completely removed, and if the temperature is too high or the carrier gas flow is not sufficient, it will easily lead to packing damage and greatly reduce the service life of the analysis tube.

If you are interested in our sorbent tube conditioning rig or have any questions, please write an e-mail to info@antiteck.com, we will reply to you as soon as possible.