PRINCIPLE OF OPERATION

Detection method
The concentration measurement of reactive silica is based on the well documented color reaction with ammoniummolybdate.

To improve the lower limit of detection, a reducing reagent is added to convert the yellow molybdosilic acid to molybdenum blue.

In the presence of phosphate, an additional reagent is added prior to the reducing agent to remove the phosphate interference.

The analysis is batch-wise, which gives the most stable results compared with other continuous flowing systems.

MEASUREMENT

Measuring Range: 0–500 ppb
0–5 ppm
Resolution: 0.01 ppb / 0.01ppm
Accuracy: 10% of reading
or +/- 0.5 ppb
Precision: 5% of reading
or +/- 0.2 ppb
Method: on-line colorimetric
Measuring volume: 20 ml
Calibration volume: 1000 ml
Reagent use: 5 liter/month
Number of Reagents: 2
with phosphate
interference: 3

SAMPLE CONDITIONS

Temperature: 5 … 40 ° C
Pressure: 0.1 … 6 bar (90 psi)
Flow rate: min. 20 ml / min.
Particles: less than 10 ppm,
no oil, no grease
pH- value: between 3 and 8

ELECTRONICS

Display: LCD Display

Alarms:	2 potential free relay outputs one concentration alarm and one system error Contact rating: 500 VA, 250 V-2A
Outputs:	4 - 20 mA free concentration range Max. load 600 ohms Resolution 6 μA (12 bit)
Options:	TTL or RS422/485 Profibus-DP Interface Multi-channel

ELECTROMAGNETIC COMPATIBILITY

Complies with EN 50081-1 and EN 50082-2 for unrestricted use in rural and industrial areas.