Signal conditioning circuit for a high input impedance differential amplifier. A1, A2 constitute op amp input stage two, and then with the A3 series consists of three op amp differential amplifier circuit. Maxwell vacuum gauge PM-2 made in the circuit, completely symmetrical A1 and A2 improve the signal to noise ratio; the circuit is almost no common mode signal amplification Maxwell vacuum gauge PM-2 core, common mode rejection ratio. The differential amplifier circuit magnification is calculated as (1) shown in the circuit Maxwell vacuum gauge, designed resistor R 1 = R2 = 24 k ohm, RG = 2k Oumu Mai's vacuum gauge PM-2 price, so the differential signal magnification of 25 times, the original signal can be amplified exactly to the desired A / D acquisition signal levels. Resistance R0 = 470 ohms, for the protection of the op amp input stage. The central processing unit with C8051F MCU chips. This class of microcontrollers instruction execution speed, low power, multi-bus interface, internal program memory space is large, and many other advantages. Its unique digital crosspoint switch, allowing its internal mapped to a variety of digital resources P0, P1, P2, P3 port pins. Meanwhile, the internal microcontroller with integrated Flash memory, you can store some system parameters, greatly simplifying the circuit design. Maxwell vacuum gauge PM-2 manufacturers _ _ Fujian Maxwell vacuum gauge measuring force since the instrument is provided by a McLeod gauge measuring the Shanghai Automation Instrumentation Co., Ltd. Shanghai Automation Instrumentation Co., force measurement (www.licesh.com) strong, credible, Zhabei District in Shanghai flow meter industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the force measured since the instrument and you work into the brilliant, for a better future!