Programming the AMPBOX signal amplifier

Programming the AMPBOX signal amplifierarticle picture
Published: Tuesday, May 10, 2011 Our radiometers have a thermopile or photo-diode detector that generates an output signal. They do not require a power supply, but the output is a very low voltage; typically in the region of 10 mV on a bright sunny day. Not every data acquisition system can measure the small output voltage from our passive solar radiometers. The AMPBOX provides a solution for this problem.

The AMPBOX takes the low voltage radiation signal and converts it to an output that will sink a controlled current between 4 mA and 20 mA. By using a shunt resistor, a higher level voltage can be produced to suit the input channels of data acquisition systems that do not accept current.

AMPBOX comes in three different gain settings;

1mV input signal represent 1mA of output
4 – 20 mA represents 0 – 16 mV

Programmed with the sensitivity of a particular instrument
Typically, 4 – 20 mA = 0 – 1600 W/m2

Adjusted for a pyrgeometer 
Programmed with the sensitivity of a particular pyrgeometer and the zero is offset to allow negative readings to be amplified
4 mA = – 600 W/m2, 16 mA = 0 W/m2, 20 mA = + 200 W/m2

The gain and zero settings need to be programmed inside the AMPBOX and up to now this has been done exclusively at the Kipp & Zonen factory in Delft, the Netherlands.

Recently some of our distributors upgraded their service levels, which allows them to program the AMPBOX themselves. Besides Kipp & Zonen in Delft and USA, the following distributors are able to program the AMPBOX; Dilus Instrumentación y Sistemas S.A in Spain, Gengenbach Messtechnik in Germany, and Eurelettronica ICAS s.r.l. in Italy.

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