Hello!
Could you please help me with the following issue: we have connected a single strain-gauge to each of the 4 zet 7010 sensors via half-bridge connection. After that the whole system has been connected to zet 7070 sensor and to a voltmeter. In the settings of the 7010 sensors we have set the following parameters: «strain-gauge — half-bridge», «measurements type — relative deformation», «sensitivity — 1». Then we have started the DC voltmeters, which were displaying various readings (1,65; 1,39; 0,66, 0,10) mV/V. As the structure with attached strain-gauges has been exposed to the load impact, the volmeter readings values increased (1,67, 1,41, 0,67, 0,12). So, finally we divided the difference values obtained by 1000 — (0,02/1000; 0,02/1000; 0,01/1000; 0,02/1000).
1. Is that the right procedure for relative deformation calculation?
2. Should the voltmeter readings be the same at the beginning of measurements process?
Thank you!

Тема

[TeamХранитель]

Hello!
Below please find answers to your questions:
«1. Is that the right procedure for relative deformation calculation?»
We have forwarded you a link to an article specifying the process of the coefficient calculation — it depends on sensitivity level of the strain-gauges as well as on their particular mounting technique.
«2. Should the voltmeter readings be the same at the beginning of measurements process?»
Yes — it is necessary to set them to zero prior to starting the measurement process, since the initial displayed value is not related to the load impact — it is actually caused by strain gauge deposition, input amplifier and cable displacement.
Yours faithfully,
LLC «ETMS» Support team

[christopher.bergensteinУчастник]

Thank you for the feedback!
Please, clarify the following issue for me:
1) Enclosed to the message I have attached screen shots of the tube testing process as well as a schematic diagram of strain gauges and sensors mounting locations. Am I right to think that in the case if the senstivity coefficient is S=1, the upper sensor’s relative deformation will be «(1,400-1,389)=0,011 mm/m=0,000011 m/m» and that of the following sensor — «(-0,0059+0,0053)=0,0006 mm/m»?

[TeamХранитель]

Hello!
1. Based on your strain-gauge deposition scheme, the coefficient value will be: S = 4/K
2. As for the rest calculations — they are correct. Please note that the second sensor deformation value will be 0,006 mm/m
Best regards,
LLC “ETMS” Support team

[Автор]

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