Why does Vemco use 69 kHz for its miniature tags when other vendors seem to use higher frequencies?
VEMCO has the capability to produce miniature tags operating at any frequency from 40 kHz to over 400 kHz. However, with few exceptions – most notably 180 kHz in noisy environments around hydroelectric dams – we have concentrated on 69 KHz which has served our clients well since this low frequency gives good range in both salt and freshwater environments. For instance, using V9s, researchers have been able to reliably detect passage (close to 100% detection rate) with VR2W monitoring receivers spaced 500 to 800 metres apart. The use of a single frequency also has the huge advantage of making possible a “worldwide network” in which every tag can be detected by any receiver in the world. The use of a low operating frequency does, however, involve compromises and as we continue to reduce the size of our transmitters, a point of diminishing returns is reached due to the very low efficiency one can achieve when driving a small transducer far below its resonant frequency. Therefore, starting
- FREQUENTLY ASK QUESTIONS ON RFID TAGS AND INLAYS (FAQs): 1. Will one of the systems using one of the frequencies of 13.56 MHz, 915 MHz and 2450 MHz be used in all applications?
- Why doesn VEMCO specify pressure accuracy for sensor tags across temperature ranges?
- Why not use frequencies spaced 5 KHz apart, the way most scanners tune?