Technical Information TI 346C/07/en/07.03 51511752 ph/redox Measurement CPM 280 Battery-driven pocket meter for ph and redox measurement Application CPM 280 is a compact pocket meter for measuring ph value and redox potential. CPM 280 is suitable for ph and redox measurement in the following fields of application: Wastewater treatment plants Drinking and surface water Laboratory and field measurement Your benefits Comfortable operation: Clear multi-function display with user guidance Precise measurement: Automatic temperature compensation via the ph combination electrode with built-in temperature sensor (NTC 30) Flexible calibration: Conventional calibration with two buffer solutions Fully automatic two-point or threepoint calibration with pre-defined buffer solutions according to DIN 19266 Fully automatic two-point or three-point calibration with technical buffer solutions by E+H Safe and cost-effective operation: Long service life with four commonly used 1.5 V batteries: approx. 3000 h Automatic power-down Dust and water-proof housing (IP 66) 3-year warranty for the measuring instrument Quality made by Endress+Hauser ISO 9001
Function and system design Measuring principle Measuring system ph measurement The ph value is used as a unit of measurement for the acidity or alkalinity of a liquid medium. The membrane glass of the electrode supplies an electrochemical potential which is dependent upon the ph value of the medium. This potential is generated by the selective penetration of H + ions through the outer layer of the membrane. An electrochemical boundary layer with an electric potential forms at this point. An integrated Ag/AgCl reference system serves as reference electrode. The transmitter converts the measured voltage into the corresponding ph value using the Nernst equation. Redox measurement The redox potential is a unit of measurement for the state of equilibria between oxidising and reducing components of a medium. Redox potential is measured similarly to the ph value. A platinum or gold electrode is used instead of ph-sensitive membrane glass. Analog to the ph measurement, an integrated Ag/AgCl reference system is used as a reference electrode. A complete measuring system comprises: CPM 280 pocket meter Norylab CPS 51 ph combination electrode with built-in NTC 30 temperature sensor, 1.5 m (4.9 ft) fixed cable and a water-proof DIN plug plastic bowl 50 ml for sampling stand used as electrode holder Input Measured variables Measuring ranges Input impedance Input current ph, redox, temperature ph 2.00... 16.00 Redox 1999... +1999 mv Temperature 5... 80 C (23... 176 F) > 1 x 10 12 Ω (at nominal operating conditions) < 1 x 10 12 A (at nominal operating conditions) Power supply Sensor connection via fixed cable Supply voltage Batteries Service life 4 x 1,5 V alkali-manganese batteries, type AA approx. 3000 h 2 Endress+Hauser
Performance characteristics Reference temperature Measured value resolution 25 C (77 F) ph 2.00... 16.00 0.01 ph Redox 1999... + 1999 mv 1 mv Temperature 5.0... 80.0 C (23... 176 F) ±0.1 K Maximum measured error a Temperature compensation ph Redox Temperature 5... 80 C (23... 176 F) ±0.01 ph of measured value at resolution 0.01 ph ±1 digit ±0.3 mv of measured value at resolution 0.1 mv ±1 digit (only valid for temperature range 15... 35 C (59... 95 F)) ±1 mv of measured value at resolution 1 mv ±1 digit ±0.1 K of measured value ±1 digit Storage temperature Environment 25... +55 C (-13... 131 F) Relative humidity < 100% Climate class 2 Ingress protection IP 66 Electrical protection class Electromagnetic compatibility III Interference emission and interference immunity according to DIN EN 50081-1 / 50081-2 Process Process temperature 5... 80 C (23... 176 F) a) according to DIN IEC 746 part 1, at nominal operating conditions Endress+Hauser 3
Mechanical construction Dimensions CPM 280 pocket meter H x W x D: 172 x 80 x 37 mm (6.8 x 3.2 x 1.5") Norylab CPS 51 sensor L x Ø: 120 x Ø12 mm (4.7 x Ø 0.5") (shaft) Case H x W x D: 115 x 355 x 305 mm (4.5 x 14.0 x 12.0") Weight CPM 280 pocket meter Norylab CPS 51 sensor Case (total weight) approx. 0.4 kg (0.9 lb.) approx. 0.1 kg (0.2 lb.) approx. 2.2 kg (4.9 lb.) Materials Measured value display CPM 280 pocket meter Norylab CPS 51 sensor LC display, two lines Housing: PP Keys: silicon Membrane glass: UNITEC Temperature sensor: zirconium Human interface Display elements UpH mv/ph C LoBat AutoCal DIN CalError AutoCalTEC ARng AR TP 1 2 3 1 2 3 TP LoBat AutoCal CalError ARng AR Status display Sensor symbol Measured value display Function and temperature display Battery status display Automatic calibration DIN: Buffer solutions acc. to DIN 19266 TEC: Buffer solutions ph 4, ph 7 Calibration error AutoRange function AutoRead function LC display C07-CPM280xx-07-06-00-xx-001.EPS Operating elements M CAL I AR O AR RUN/ ENTER CAL M Start instrument AutoRead function (Hold function) Start AutoRead measurement, configuration, confirm measured value Start calibration Select measuring mode (ph / Redox) or switch to measuring mode RUN/ENTER Key assignment C07-CPM280xx-19-06-00-xx-001.EPS 4 Endress+Hauser
Certificates and approvals 4 approval Declaration of conformity The product meets the legal requirements of the harmonised European standards. Endress+Hauser confirms compliance with the standards by affixing the 4 symbol. Ordering information Order number ph pocket meter CPM 280 Order no.: 51510538 Scope of delivery Scope of delivery The measuring set comprises: 1 CPM 280 pocket meter 1 Norylab CPS 51 ph combination electrode with built-in NTC 30 temperature sensor, 1.5 m (4.9 ft) fixed cable and a water-proof DIN plug 2 plastic bottles with technical buffer solutions ph 4 and ph 7, 50 ml each 1 plastic bottle with electrolyte solution 3 mol/l KCl, 50 ml 1 plastic bowl 50 ml 1 stand used as electrode holder 4 alkali-manganese batteries 1.5 V 1 solid plastic case made from PP with integrated measuring point and separate pocket for ph electrode and accessories 1 Operating Instructions BA 346C/07/b4 Accessories and spare parts Electrodes ph combination electrode with built-in temperature sensor, 1.5 m (4.9 ft) fixed cable and waterproof DIN plug; application range 1... 12 ph, 5... 80 C (23... 176 F); Order no.: CPS51-7EK2FDA Platinum redox electrode with NSA plug-in head and plastic shaft; application range 1... 12 ph, 5... 80 C (23... 176 F); Order no.: CPS52-0PK2FDA Buffer solutions ph buffer solution CPY 2: ph 4.0; 20 x 20 ml for single use Order no.: CPY2-D ph buffer solution CPY 2: ph 4.0; 100 ml refill bottle Order no.: CPY2-0 ph buffer solution CPY 2: ph 4.0; 1000 ml refill bottle Order no.: CPY2-1 ph buffer solution CPY 2: ph 7.0; 20 x 20 ml for single use Order no.: CPY2-E ph buffer solution CPY 2: ph 7.0; 100 ml refill bottle Order no.: CPY2-2 ph buffer solution CPY 2: ph 7.0; 1000 ml refill bottle Order no.: CPY2-3 Redox buffer solution CPY 3: 220 mv, ph 7.0; 100 ml refill bottle; Order no.: CPY3-0 KCl electrolyte solution CPY 4: 3.0 mol/l. 100 ml refill bottle; Order no.: CPY4-1 Endress+Hauser 5
Supplementary documentation Pocket meter CPM 280, Operating Instructions BA 346C/07/b4, Order no.: 51510871 Norylab CPS 51, Technical Information TI 031C/07/en, Order no.: 50054652 Norylab CPS 52, Technical Information TI 031C/07/en, Order no.: 50054652 6 Endress+Hauser
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Endress+Hauser GmbH+Co. KG Instruments International P.O. Box 2222 D-79574 Weil am Rhein Germany Tel. (07621) 975-02 Tx 773926 Fax (07621) 975 345 e-mail: info@ii.endress.com Internet: http://www.endress.com 11.01 TI 346C/07/en/07.03 51511752 Printed in Germany / FM+SGML 6.0 / DT