Dear participants,

Due to some questions about the document “Procedure Instruction” from our participants, two additional points are presented as follows:

Question 1: Which ambient temperature shall be used for the determination of the temperature class?
Answer: The temperature tests shall be performed under a normal ambient temperature range from -20°C to +40°C.
Therefore, the basis ambient temperature for the determination of the temperature class shall be +40°C.

Question 2: What's the meaning of some points in section 3.3 “Handling and operational Instructions” on page 5?
Answer: The additional information for following points are shown in red.

The heating block and three plates are assembled in accordance with the following important requirements at PTB and are ready for use.
Please check the torque of each screw after receiving the test sample. It’s possible that during the shipping the screws are loose:
The Test Sample is completely prepared (ready for tests) and has to beonly checked the torque of each screw before test by the laboratory.

·    To improve thermal transmission, a very thin layer of thermal compound or copper Lubricating paste should be applied between the heating block and the plate.

The descried preparation phase of the test sample is used for some special cases, e.g. due to broken glass plate, a spare plate should be prepared with the supplied thermal compound following this description.

·    To protect the glass plate against damage, four washers made of PTFE have to be used for each screw at the glass surface.

Other four washers are provided just as replacement.

·    The three plates should be screwed on the heating block with a nominal torque of ca. 0.5 Nm for glass and plastic plate and ca. 1.5 Nm for copper plate.
     The positions for those three plates are shown below.
The torque of each screw has to be checked, which is 0.5 Nm for glass and plastic plate and 1.5 Nm for copper plate


I sincerely apologize for the inconvenience this may have caused. Thank you for your understanding and your patience.

Best regards,
Jia