One Sweden customer need one element use for a personal alarm,his alarm sound is a sound wailing between 2khz and 5khz.The customer hope us to recommend one element so can reach maximum sound pressure.

Firstly,we confirm the piezo element size with customer,and he prefer 20mm & 27mm piezo element.Consider application is for personal alarm,we recommend 27mm piezo element with 4Khz. When customer use our samples,the test result is not good,the frequency and sound is not ideal.so we confirm the installation method with customer again,last we find out the reason,the customer using edge mount.

We told the customer when using edge mount,the resonant frequency of the piezo buzzer is only 64% of the resonant frequency of the same piezo element in open air.in order to reach a resonant frequency of 3.6 khz his personal alarm, he need to choose a piezo element with a resonant frequency of 5.625 khz.But if cutomer use node mount,the frequency and sound will be better,furthermore,we take figure of our piezo buzzer which use same piezo element with same node mount to customer.He take our advice,the test result is perfect and he places the order from us.