Operating manual MPP 350 Multi parameter probe for pH, dissolved oxygen, conductivity and temperature ba75434e02 07/2005
MPP 350 Accuracy when going to press Copyright 2 The use of advanced technology and the high quality standard of our instruments are the result of continuous development. This may result in differences between this operating manual and your instrument. Also, we cannot guarantee that there are absolutely no errors in this manual. Therefore, we are sure you will understand that we cannot accept any legal claims resulting from the data, figures or descriptions.
MPP 350 Contents 1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 1.2 2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 3.2 4 5 5.4 5.5 5.6 5.7 07/2005 Error symptoms of D.O. measurement . . . . . . . . . . . . . . . . . . 22 Error symptoms of conductivity measurement . . . . . . . . . . . .
Overview MPP 350 1 Overview 1.1 Structure and function The MPP 350 multi parameter probe is a modularly constructed sensor for pH, dissolved oxygen, conductivity and temperature.
MPP 350 Overview Basic module Conductivity measuring cell 1 pH electrode 14 4 5, 6 16 7 15 D. O.
Overview MPP 350 The basic module is the basic component of the operable sensor. It can be used as a stand-alone conductivity measuring cell with temperature sensor. By mounting the D. O. module and/or pH electrode the basic module can be extended to form a multi parameter probe for pH, dissolved oxygen, conductivity and temperature. The D.O. module is connected to the basic module via a watertight, threepole plug connection.
MPP 350 Safety 2 Safety This operating manual contains special instructions that must be followed during the operation of the sensor. Always keep this operating manual in the vicinity of the sensor. Special user qualifications The membrane cap of the D. O. module is filled with a small amount of an alkaline electrolyte solution. All maintenance work that requires dealing with the electrolyte solution must only be carried out by persons who know how to deal with chemicals safely.
Commissioning MPP 350 Note The membrane cap that is mounted on the D.O. sensor for delivery serves mainly as a transport protection. Depending on the duration of the transport and storage period, it may have a shortened operational lifetime. If the measuring system cannot be calibrated (error message on the instrument), please proceed according to section 5.3 D.O. MODULE: CHANGING THE ELECTROLYTE SOLUTION AND MEMBRANE CAP. 3.1.
MPP 350 Commissioning 5 Small parts (adapters etc...) 6 MPP 350 with OxiCal®-MPP 7 Connection cable 12 Polishing film 13 pH/cond calibration vessel 3.2 Getting the sensor ready for measuring 3.2.1 Measurements without D. O. module Make sure that the plug connector of the conductivity measuring cell is tightly closed with the suitable closing cap. When mounted, the closing cap (1) must be screwed on up to the stop.
Commissioning MPP 350 3.2.3 Mounting the D. O. module Make sure that the D.O. module and conductivity measuring cell are screwed together tightly. When mounted, the cap nut of the D.O. module has to be screwed on up to the stop. 3 Before screwing on the D.O. module, check the following points: ! The sealing (3) must be clean and evenly positioned in the groove. 2 ! The plug connection must be clean and dry on both sides. 1 Screwing on the D.O. module Position the D.O.
MPP 350 Commissioning 3.2.4 Mounting the pH electrode Mount the electrode: ! If necessary, remove the plug from the electrode receptacle (1). 1 ! Protect the pH electrode with the watering cap (4). ! Push the electrode (2) into the electrode receptacle up to the stop. When doing so make sure the sealing (3) is clean and greased and correctly positioned in the groove. 3 ! Remove the watering cap (4). ! Screw on the protective hood.
Measuring / Operation MPP 350 4 Measuring / Operation 4.1 Calibration 4.1.1 Calibrating for D. O. measurement To calibrate the D.O. module, use the OxiCal®-MPP calibration and storage vessel (white). It is screwed on the sensor instead of the protective hood. Make sure that the sponge in the calibration vessel is always moist. Moisten the sponge: ! Unscrew the lid (1). ! Take out the sponge (2) out of the lid, wet it, then slightly squeeze it out.
MPP 350 Measuring / Operation 4.2 Measuring Please always observe the required minimum immersion depth and the minimum approach flow that is important for D.O. measurements (see chapter 7 TECHNICAL DATA). The minimum flow can be provided in different ways, e. g.: ! The flow of the water to be measured is sufficient (aeration tank, water pipe, stream) ! Slowly pull the sensor through the water by hand (lake, container), or ! Use a flow aid, e. g.
Maintenance, cleaning, replacement For your safety MPP 350 5 Maintenance, cleaning, replacement 5.1 General maintenance instructions Note the following safety instructions when handling electrolyte and cleaning solutions: Caution The ELY/G electrolyte solution and the RL/G cleaning solution irritate the eyes and skin. Observe the following points when handling the solutions: ! During working activities, always wear suitable protective gloves and protective goggles/face shield.
MPP 350 Maintenance, cleaning, replacement 5.2 Basic module and D.O. module Outside cleaning Contamination Cleaning procedure Lime sediments Immerse in acetic acid (volume share = 20 %) for 1 minute Fat/oil Clean with warm water that contains washing-up liquid After cleaning, thoroughly rinse with deionized water and recalibrate if necessary. pH electrode ba75434e02 07/2005 For further notes concerning the cleaning of the electrode refer to the electrode operating manual.
Maintenance, cleaning, replacement 5.3 MPP 350 D.O. module: Changing the electrolyte solution and membrane cap Caution Before starting to work with the sensor, please note the GENERAL MAINTENANCE INSTRUCTIONS on page 14. General information WTW delivers the D.O. module ready to use (see section 3). The electrolyte solution and membrane cap must only be replaced if: ! a calibration error occurs and the membrane is heavily contaminated ! the membrane is damaged ! the electrolyte solution is exhausted.
Maintenance, cleaning, replacement G ELY/ MPP 350 ELY/ G Carefully shake off the drops of water. Fill a new membrane cap with ELY/G electrolyte solution. Remove any air bubbles by carefully tapping the membrane cap. Additionally, you can prevent air bubbles by throwing the first filling away and refilling the membrane cap. Ventilation area points upwards 4 mm Thoroughly rinse the sensor head with electrolyte solution.
Maintenance, cleaning, replacement 5.4 MPP 350 D.O. module: Cleaning the electrodes Caution Before starting to work with the sensor, please note the GENERAL MAINTENANCE INSTRUCTIONS on page 14. General information Cleaning is only required in cases of slopes too small or too large (sensor cannot be calibrated) that cannot be resolved by changing the membrane cap and electrolyte solution. Cleaning the electrodes SF 300 Unscrew the membrane cap.
MPP 350 Maintenance, cleaning, replacement H2O Carefully shake off the drops of water. Remove any air bubbles by carefully tapping the membrane cap. Additionally, you can prevent air bubbles by throwing the first filling away and refilling the membrane cap. Rinse the sensor head with electrolyte solution. G Water the counter electrode in deionized water for at least 10 minutes. ELY/ ELY/ G Thoroughly rinse the sensor head with deionized water.
Maintenance, cleaning, replacement MPP 350 Note For measurements under high pressure the filling must be completely free of air bubbles. Readiness to measure After approx. 30 to 50 minutes, the sensor is ready for operation. Subsequently calibrate the sensor. Note If you want to measure very low D.O. concentrations (< 0.5 % saturation), we recommend to let the sensor rest overnight and then calibrate it. 5.5 Checking the D.O. module for freedom from zero-current The D.O.
MPP 350 Maintenance, cleaning, replacement 5.7 Disposal Caution The ELY/G electrolyte solution irritates eyes and skin. When dealing with the ELY/G electrolyte solution, observe the following points: ! During working activities, always wear suitable protective gloves and protective goggles/face shield. ! If it comes into contact with the skin, rinse thoroughly with water and immediately change contaminated clothing.
What to do if... MPP 350 6 What to do if... 6.1 Error symptoms of D.O. measurement Error symptom Cause Remedy No D.O. display – No connection between meter and – Check connection between meter sensor and sensor – D.O. module not mounted – Check the plug-in connection, properly clean the contacts as necessary – Cable defective – Return the sensor The sensor is in the air and the display shows 0.
MPP 350 What to do if... 6.
Technical data General features MPP 350 7 Technical data 7.1 Basic module with conductivity measuring cell Measuring principle Four-electrode measurement Cell constant 0.475 cm-1 ±1.5 % Temperature sensor integrated NTC 30 (30 kΩ/ 25 °C) 287.5 Dimensions (in mm) 247 41.5 Weight Materials 24 Probe approx. 135 g (without cable, sinker, pH electrode and D.O. module) Sinker approx.
MPP 350 Technical data Connection cable Lengths Diameter 6,1 mm Smallest allowed bend radius Permanent bend: 60 mm Single time or short time bend>: 35 mm Material Kabelmantel PVC, stabilisiert Lengths Connector for D.O.
Technical data MPP 350 7.2 General features Dissolved oxygen (D.O.) module Measuring principle Membrane covered galvanic sensor Temperature compensation IMT compensation (calculated by the meter) Dimensions (in mm) Weight Materials Plug connection Pressure resistance approx.
MPP 350 Technical data Measurement conditions Storage conditions Characteristic data on delivery ba75434e02 07/2005 Measuring ranges at 20 °C 0 ... 50 mg/l D.O. 0 ... 600 % D.O. saturation 0 ... 1250 mbar D.O. partial pressure Polarization time min. 30 ... 50 min after changing the electrolyte, it is not necessary to connect the sensor to the meter for polarization Temperature range 0 ... 50 °C Max. allowed overpressure 106 Pa (10 bar) Depth of immersion with conductivity basic module min.
Technical data MPP 350 Pin assignment 28 ba75434e02 07/2005
MPP 350 Wear parts and accessories 8 Wear parts and maintenance equipment Accessories Wear parts and accessories Description Model Order no.
Wear parts and accessories 30 MPP 350 ba75434e02 07/2005
