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3 INTEGRATING THE MAS-1

3. The MAS-1 requires only two conductors, so long lines are both

lower in noise and less expensive.

4. With the MAS-1 sensor the source impedance is small, and a

current loop is highly immune to noise on the line.

5. Measured voltage can be tailored to a particular data acquisi-

tion system simply by adjusting the value of R

application might be to use a MAS-1 with a 12 volt supply

and a R

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product of the current and the resistance (Equation 1), so for

4-20 mA it would be 4 to 29 mV.

3.2

Testing the Sensor

After integrating the MAS-1 into your PLC or other data acquisition

system, it is always a good idea to test the sensor output to verify

that it is functioning correctly with your system. Two convenient

test conditions are surroundeding the sesnor with air or water. To

test in air, suspend the sensor form the cable, making sure that it is

at least six inches from any object. To test in water, place the sensor

in a bucket of tap water (do not use deionized or distilled water).

The entire sensor (prongs + black plastic electronics portion) should

be immersed in water, and should be at least two inches from any

container surface. Under these conditions, the sensor should trans-

mit in the following ranges (approximate). The air between 3.4 to

4.7 mA and tap water: 18.1 to 22.4 mA.

Note: Sensor output can go above 20 mA and below 4 mA

value of 1 ohm. The output voltage range is the

MAS-1

. A typical

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