Hard Disk Monitoring

On the "Temperature" tab of each drive, I am seeing

It is recommended to calibrate the temperature and set the temperature offset on the S.M.A.R.T. page. This way later the correct temperature value will be displayed.

That seems to imply that the drive's temperature reporting may be incorrect and it should be adjusted.

That being the case, how would one know what the correct temperature is?

Or do I misunderstand the admonition?

You are absolutely correct.

It is recommended to verify if the drive temperature sensor is accurate and adjust the proper S.M.A.R.T. attribute (194 or 190) if required by entering the difference between the real and reported temperature to the Offset field.

This is more important on some models, for example many Samsung drives usually show them 5-8 Celsius cooler than their actual temperature. In contrast, some WD models showed much higher temperatures than the actual.

You can check the correct temperature by an external temperature sensor, for example an infrared thermometer.
Of course it may not be available or possible in all cases.
A very good estimate can be determined by checking the first displayed temperature immediately after starting the computer and comparing the value with the environment (room, office) temperature. At this time, the CPU, video card or other components are not too warm and they do not affect the temperature of the hard disk. Of course this is true only if the computer had enough time to cool down to the environment temperature (it was powered OFF for at least 8 hours).

For more information, please check the Help -> Appendix -> Temperature Calibration section.

I tried to calibrate temperature of my hard drive. After 8 hours powered off my computer, when I power on I noticed that the temperature is 24 celcius with same my room temperature. After 5 minutes it is increased to 27 celcius degree.

Usually my drive (seagate 1 terabyte-sata3-ncq) works at 30 - 31 celcius degree although it has a external hard drive fan.

Is it normal ?

It is completely normal.

If the first measured temperature (24 Celsius) matches the room temperature AND then you see the temperature increasing when the drive is working, we can say the temperature sensor is working as should and provide accurate results.

30-31 Celsius is excellent level. Usually external drives have higher temperatures but if there's a fan, it keeps the drive in this good temperature range.
Maybe if you perform disk testing (Disk -> Extended self test in Hard Disk Sentinel) or a virus scan / defragmentation, you will see some increase in the temperature but I suspect it will be still nice, thanks for the fan.

maverick wrote:I tried to calibrate temperature of my hard drive. After 8 hours powered off my computer, when I power on I noticed that the temperature is 24 celcius with same my room temperature. After 5 minutes it is increased to 27 celcius degree.

Usually my drive (seagate 1 terabyte-sata3-ncq) works at 30 - 31 celcius degree although it has a external hard drive fan.

Is it normal ?