If your material does not show deflection in the temperature range, it possibly is due to:

You are making a bad programming of the software for acquiring the information.

You can go to signals and put: weight (Y) and temperature (X).

I have seteram labsys TGA. I think you also check the axis in program. You must check the your programing. TG data must be in axis on the left or right side. hold the TG data and move it true place. Or you can also see it when you export the file as ASCII or excel. If you dont see you have big problem. If so, you can contact me again. The best.

If you have a melting or recrystallization transition you will see a DTA signal (latent heat) but no TGA change if there is no decomposition or evaporation. It is a fairly common event.

Irfan... To be sure of the right cause for such a problem, you need to run one of the standard materials like calcium oxalate monohydrate. Here all the three DTA peaks are accompanied with weight loss signal. If TGA signal does not appear, it is a technical fault. Call an engineer.. Good luck

TGA analysis depend on the weight. So if your phenomena does notshow any weigt loss (e.g decomposition) or weight gain (e.g oxidation). You will not get any deflesion of the thermogram. Some example whereyou can get DTA signals without change in TGA signals are (melting, recrystallization, glass transition..)

Thank you dear friends. All the answers are very supportive. Let me clear, we are not getting TG even for standard samples. I am feeling that the balance may not be working. @ali Delibas I will follow your instructions and will update you.

Dear İrfan, seteram balance is very sensitive. ı think seteram is not good choice. we had many problems. 

Hope you have already resolved it. As you have said, you have tested Standard CRM (Certified Reference Materials) or other samples and not getting TG curve. If you are getting DTA curve only (simultaneous DTA/TGA rod) the causes are 1) TG saturation, means the balance head (guessing your system has vertical balance) need to be adjusted manually in null position (use some weight shots as counter weight).In such case, you will get a flat horizontal TG line. 2) The balance mechanism/circuit is faulty due to improper handling. Since the transducer rod connection has no problem, thus it giving a signal of microvolt variation (DTA) only.

In case you are not getting any curves using your DTA/TGA thermocouple sensor. Then, the reasons are 1) The thermocouple malfunction (e.g., platinum/rhodium wire tear inside ceramic jacket), 2) transducer connection port is not working or the command module unable to acquire data (e.g., by data acquisition software).

Otherwise, please make sure your PC/desktop can recognise the transducer via command module via cables (e.g., Ethernet cables). Then, check your data acquisition and processing software, it should recognize your apparatus (e.g., declaring the device). 

The additional notes, as already described by Gyorgy Banhegyi and Djalal Trache. Once you have resolved the issue, try non-isothermal heat treatment on common compounds (CaCO3) with known enthalpy of transitions and TG variations. By performing several test in identical test conditions will ensure adjustment and calibration of your TGA module.

Just to help you understand thermocouple malfunctioning, I am attaching a DSC/TGA (supplied by Setaram) wire damaged transducer rod (corrosive vapor induced tear).

Thanks dear friends. I am close to resolve the issue and will update you once I am successful.

Thank you all for this valuable input.

Dear Mahdi, plz elaborate the null balance procedure and it's importance. Moreover, plz also tell abt the taring procedure. E.g. when we put empty crucible and after placing sample.

I would start with checking your balance performance - reference weights should have come with the instrument. Tare the instrument and load the reference weight. If it is measuring off the known weight beyond the error associated with the balance, that will give you an indication of how well the balance is performing. If it is significantly off - or if the weight is unstable - there may be something wrong with the balance. This could be as simple as needing a recalibration or as complicated as needing a repair. 

To check balance performance at elevated temperature: Run a reference with a known material (high purity Calcium Oxalate works very well!) with a well-characterized decomposition with well-known mass loss at each step of decomposition. This will let you know if there is something wrong with the TG side of your TGA at higher temperatures. 

The rod your image shows looks to me like it comes from a Setsys or Line 92 instrument - theses instruments have drop-down balances which in most cases are designed with an inert gas sweep of the balance area to protect the balance from the corrosive vapors that may be released from the sample. Therefore, I do not think that it is likely that the TG part of the TGA is malfunctioning, as the actual measurement happens at the balance and not at the rod. Most likely it is a situation as described by the users above, where you have a phase change or a glass transition which is not associated with a mass change.

That said - it's never a bad idea to check the balance performance and temperature calibration - they should be checked periodically and recalibrated when any significant change to the procedure takes place (a change in ramp rate, atmosphere, temperature profile, etc) - especially for your DTA accuracy, this is of high importance.