These transimpedance amplifiers are particularly useful for the measurement of current from photodiodes. The output is a voltage linearly proportional to input current and thus, to input power in photodiode monitoring applications. Their fast response time at high signal-noise-ratio makes the TZA series particularly useful in systems control feedback loops. These amplifiers' high sensitivity and large dynamic range allow measurement of a wide range of optical sources such as lasers and LEDs via a variety of photodiodes for these applications such as Si and InGaAs. The TZA series is insensitive to electromagnetic interference by design, an important factor when working in „dirty" industrial environments. These units are provided in compact OEM style cases with gullwing mounts or as a modular 19" rack mount system. The rack system allows the user to conveniently upgrade the channel count of an existing unit.