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本帖最后由 wdhd 于 2016-4-8 11:20 编辑
好,学习学习.不过我狂鄙视随便引用别人帖子的人,有墨水还好,没墨水就丢人了.
关于ICP、IEPE我引用别人的文章，这个详细：
ICP, IEPE, PIEZOTRON SENSORHISTORY, NEWS, & TECHNOLOGY
Patent and Trademark Antics Generate Conflict
The beginning of things is often vague, controversial, and confusing. The origin of the valuable, popular, ICP Piezotron (Integrated Circuit Piezoelectric) sensor concept in the mid 1960s is no exception. As usual, a number of gifted, diverse individuals, unaware of the work of others, were involved.
The concept was first embodied in Piezotron® sensors in the year, 1965. When dramatically introduced by the original Kistler Instrument Corporation (KIC/USA) at the 1965 ISA Conference and Exhibit in New Orleans, a piezoelectric sensor operating over two ordinary wires amazed and dumbfounded the instrumentation community. Endevco called it the Confusatron on cards quickly printed and distributed to expose the suspected trick involved. Headlines of fake newspapers posted at the exhibit read “Lallygag Fails.”
From this lively beginning, the two-wire ICP Piezotron idea was destined to become one of the real success stories of modern technology.
The revolutionary ICP concept is now a de facto sensor-industry standard. Most modern recording and display instruments feature an ICP input. Over a dozen different manufacturers market ICP sensors under various aliases, including Isotron®, DeltaTron®, LIVM®, CCLD®, ACOtron®, Constant Current, CCM, and now, IEPE.
Like computers, ICP Piezotron sensors are a marvel of modern technology. Electrostatically operating over two ordinary wires, they simply and naturally mate a charge-generating crystal with a charge-operated transistor. The low output impedance of the internal isolation amplifier practically eliminates interaction with external instruments from appreciably changing the signal. Newer, sophisticated versions include overload protection, integral active filters, integration, current-mode operation, and self-identifying memory.
Rationalizing, some people now consider the ICP idea obvious, not really an invention. The record seems to support this view, although several patents were issued to different people for the same idea. Apparently the patent office also was confused by the new technology.
The key patent, US 3,294,988 filed Sept. 24, 1964, was awarded to David Packard, an executive of Hewlett Packard fame, who claimed an intimate mechanical and electrical mating of a piezoelectric or pyroelectric crystal with an insulated-gate field-effect transistor. He apparently ssumed or knew that the basic idea and two-wire operation which he diagrammed were either obvious or already public domain. They were not claimed as inventions.
Much later, KIAG, a Swiss offshoot of the original Kistler Company (KIC), acquired the remnants of original KIC Company from Sundstrand, and obtained rights to a KIC Piezotron® patent. Then in a French court that naturally favors European interests, KIAG charged that the ICP products of PCB infringed. They lost. The court ruled that explicit prior art contained in the Packard patent invalidated the KIC patent.
About the same time as the Packard invention, the original US Kistler (KIC) Piezotron® creation started with a crude marketing idea to operate a piezoelectric sensor with a built-in transistor amplifier over two ordinary wires. When presented with the idea, the Kistler engineering manager almost immediately saw that one of a new family of insulated-gate transistors could do the job much more simply and elegantly. It did not need a bias voltage on the gate.
A second transistor was added to lower the output impedance even further. Walter Kistler coined the name, Piezotron®.
A special, ultra-high-value, tera-ohm resistor needed to slowly discharge the crystal capacitance and automatically zero the amplifier input was laboriously developed by a close associate, Fred Oettel, who started Eltec Instruments to manufacture it.
About the same time, Phillips Electronics independently introduced an integrated-circuit version of the same two transistor amplifier. As a result, the Piezotron® quickly evolved into an I.C. Piezotron®, or more simply an ICP, which pCB later chose to further develop and promote.
PCB Electronics operated for a year as a sole proprietorship promoting the ICP concept, before being incorporated as PCB Piezotronics late in the year 1967. But the increasingly popular ICP term was not registered as a trademark until 1990, and then deceptively as I.C.P. The first application was rightfully rejected as a descriptive, generic term. The claimed 1968 date and place of origin is still not correct, per a published 1967 ISA Paper.
Incredibly, PCB then sued arch-rival KIC/KIAG for infringement of the I.C.P. trademark. The Swiss company countered claiming infringement of a mounting adapter patent. Kistler won on both counts. KIC and others now freely use the technical term ICP in ads and literature.
IEPE (Integral Electronics Piezoelectric) is the IEST (Institute of Environmental Science and Technology) newly adopted term to identify ICP type piezoelectric sensors. According to a former president of Endevco, the term IEPE was in use at Endevco as early as 1980. It served primarily as an alternate way of describing ICP sensors. Although some systems people have adopted the awkward IEPE term, most sensor manufacturers continue to talk ICP, while publicly displaying their own alias terminology mentioned above.
The awe-inspiring ICP Piezotron® development is one of the truly great accomplishments of the instrumentation community, although not one of its more noble ones. The effort involved many dedicated engineers and technicians,as well as a few unscrupulous, dishonest administrators.
When now often applied to polarized condenser microphones, ICP technology ought to be more generally termed ICE (integral-circuit-electrostatic), or ICEM.
Bob Lally, the author, can be reached at: lally@peopling.net. He helped start and build the original Kistler Instrument Corporation, founded PCB, conceived the two-wire ICP idea, and coined the term, ICP.
最后哪个传感器好我也懒得说了，反正我也不是卖传感器的，大家自己用的好就OK啦!
[ 本帖最后由 VIz_Jaqtaar 于 2008-1-26 20:13 编辑 ]
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发表于 2007-11-10 19:02
提升卡
变色卡
显身卡
发表于 2008-1-25 14:41
