Metso 3300 Series, Manual

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MANUAL
Manual Series 3300 2. InstALLAtIon
2.9 Maintaining the sensor operation
Cleaning the sensor
Cleaning may be necessary if deposits have built up to an
extent that affects the cell constant of the electrode part.
When cleaning the sensor do not use hard material to
scrape or grind. Use a soft brush or cloth and a suitable
cleaning remedy depending on the nature of the depos-
its. Be carefull not to damage the electrodes as this might
affect the accuracy of the sensor.
Chemical cleaning can be applied by using any reagent,
that will not affect the sensor material. Sulphamic acid
(NH2SO3H) is recommended. Use 250 g in 1 litre of water.
Heat the water to ease dissolving. The solution can be
used cold or warm.
List of usable cleaning acids for sensors.
Insert for max. 2h at 30°C~ 86°F
Acetic acid CH3 COOH
Citric acid C3H4 (OH) (COOH)3
Formic acid HCOOH
Lactic acid C3H4 (OH) COOH
Nitric acid HNO3
Oxalic acid (COOH)2 , max. 40% w/w
Phosphoric acid H3PO4
Sulphamic acid NH2SO3H
Sulphuric acid H2SO4 , max. 30% w/w
Tartaric acid C2H2 (OH)2 (COOH)2
Warning! Do not use:
Hydrochloric acid HCl
Hydrofluoric acid HF
Commercially available cleaning chemicals may contain
corrosion inhibitors, that can create an electrical isolating
layer on the electrodes. This will result in a high scaling
signal after cleaning and a degraded performance of the
sensor.
Removing a sluice sensor
Maximum pressure during withdrawal: 5 bar
1. Unscrew the nut while holding back the sensor to
avoid a violent push-out.
2. Let the sensor move out under control until the stop.
3. Close the ball valve.
4. Unscrew the sensor from the sluice chamber.
Mounting a sluice sensor
1. Check the O-ring for damage before remounting the
sensor.
2. Open the ball valve
3. Insert the sensor and tighten the 1” nut.
Sensor type 4216 4223 4226
Length (mm) 248 228 338