Measure of conductivity in water for controlling NH3 leak

Hi,

I have following problem:

I measure the conductivity of the water to regulate the drainwater of the condenser-water circulation. The conductivity becomes on ca. 1,500 µS/cm held. In addition I would like however an upper limit by 2,000 µs/cm, that have to control the water circulation on entering NH3.

Would ask:
1) the conductivity increases actually in supplement of NH3?

2) if no, what happens otherwise?

3)
if the detection is possible over the conductivity, how many NH3 (kg) must arrive into the water, until the value of 2,000 µs/cm reached (difference 500 µs/cm)?

4)
following calculation correct?
NH3-reaction with water becomes to ammonia chloride with a conductivity of 20.4 µs/cm (is the value correct?) Difference: 500 / 20.4 -> 24% solution?

I know about pH-Value-Measurements and Ammonion NH4 detection. But I want spend money by using the conductivity-measurement for both.

thanks
moeller