EUTECH INSTRUMENTS EC-ISA-PB1-BT Instruction Manual Download Page 19

Instruction Manual 

 

Lead Electrode

 

 

17

TROUBLESHOOTING GUIDE 

 
The goal of troubleshooting is the isolation of a problem through checking each of the system 
components in turn:

 

the meter, the glass-ware, the electrodes, the standards and reagents, the 

sample, and the technique. 

 

Meter 

The meter may be checked by following the check-out procedure in the instrument instruction 
manual. 

Glass-ware/Plastic-ware 

Clean glass-ware is essential for good measurement. Be sure to wash the glass-ware/plastic-ware 
well with a mild detergent and rinse very well with distilled or deionized water. Clean glass-ware 
will drain without leaving water droplets behind. 
 

Electrodes 

The electrodes may be checked by using the procedure found in the sections entitled 

Electrode 

Slope Check

 

1. 

Be sure to use distilled or deionized water when following the procedures given in 

Electrode Slope Check

 
2. 

If the electrode fails to respond as expected, see the sections 

Measuring Hints

 

and 

Electrode Response.

  Repeat the slope check. 

 
3. 

If the electrodes still fail to respond as expected, substitute another lead ion electrode that 
is known to be in good working order for the questionable electrode. If the problem 
persists and you are using an electrode pair, try the same routine with a working reference 
electrode. 

 
4. 

If the problem persists, the reagent may be of poor quality, interferences in the sample may 
be present or the technique may be faulty. (See 

Standards and ReagentsSample

, and 

Technique

 

sections below.) 

 
5. 

If another electrode is not available for test purposes, or if the electrode in use is suspect, 
review the instruction manual and be sure to: 

- Clean and rinse the electrodes thoroughly. 
- Prepare the electrodes properly. 
- Use the proper filling solution. 
- Adjust the pH and the ionic strength of the solution by the use of the proper ISA. 
- Measure correctly and accurately. 
- Review

 

TROUBLESHOOTING HINTS

.

 

 

Sample 

Look for possible interferences, complexing agents, or substances which could affect the response 
or physically damage the sensing electrode (or the reference electrode) if the electrodes work 
perfectly in the standard, but not in the sample. Try to determine the composition of the samples 
prior to testing to eliminate a problem before it starts. (See sections on 

Measuring HintsSample 

Requirements

, and 

Interferences

.) 

 

Summary of Contents for EC-ISA-PB1-BT

Page 1: ...EUTECH INSTRUMENTS PTE LTD INSTRUCTION MANUAL LEAD ION ELECTRODE...

Page 2: ...Lead using an ion meter 7 Low Level Lead Determination using a pH mV meter 8 Low Level Lead Determination using an ion meter 9 Titration 10 Titration of Lead 10 Titration of Sulfate 11 ELECTRODE CHAR...

Page 3: ...nations using a pH mV meter ERROR BOOKMARK NOT DEFINED TITRATION Error Bookmark not defined Titration of Sulfide ERROR BOOKMARK NOT DEFINED Titration of Silver ERROR BOOKMARK NOT DEFINED Low Level Chl...

Page 4: ...solution and standard preparation 2 Methanol formaldehyde solution To prepare this solution from your own laboratory stock add 3 drops of 37 formaldehyde to 1 000 ml of reagent grade methanol This sol...

Page 5: ...l of methanol formaldehyde solution and 50 ml of distilled water Add 2 ml of ISA Place the beaker on a magnetic stirrer and begin stirring at a constant rate After assuring that the meter is in the mi...

Page 6: ...n temperature To counteract this effect place a piece of insulation material such as styrofoam sheet between the stirrer and beaker Use plastic lab ware for all low level measurements in order to mini...

Page 7: ...ter 1 By serial dilution prepare 10 2 M 10 3 M and 10 4 M or 100 ppm and 10 ppm standards from the 0 1M or 1 000 ppm standards Prepare standards with a composition similar to the samples if the sample...

Page 8: ...ar portion of the curve requires the use of low level procedures 6 To a clean dry 150 ml beaker add 50 ml of the sample 50 ml of methanol formaldehyde solution and 2 ml of ISA Place the beaker on the...

Page 9: ...on the magnetic stirrer and begin stirring at a constant rate 7 Lower the electrode tips into the solution 8 Adjust the meter to the concentration of the lead standard and fix the value in the memory...

Page 10: ...a 150 ml plastic beaker Place the beaker on the magnetic stirrer and begin stirring at a constant rate 4 Place the electrode tips in the solution Assure that the meter is in the mV mode 5 Add incremen...

Page 11: ...low level ISA to a 150 ml plastic beaker Place the beaker on the magnetic stirrer and begin stirring at a constant rate Lower the electrode tips into the solution When the reading has stabilized fix t...

Page 12: ...lask gently to dissolve the solid Fill the flask to the mark with distilled water cap and upend the flask several times to mix the solution 2 Fill a 50 ml buret with the EDTA solution Pipet 50 ml of t...

Page 13: ...re ideal for this titration method If the sulfate samples are more dilute the lead perchlorate titrant should be correspondingly more dilute 1 Prepare 0 01M lead perchlorate titrant by pipeting 100 ml...

Page 14: ...m the unknown is calculated as follows Vt Mt MSO4 2 VSO4 2 where MSO4 2 concentration of sulfate ion in the unknown moles liter Vt volume of lead added at endpoint Mt lead concentration moles liter VS...

Page 15: ...y pH adjustment to above pH 4 by the addition of NaOH Precipitation and Complexation Sulfide phosphate hydroxide and other ions precipitate insoluble lead salts The level of lead ion the level of the...

Page 16: ...dy with one hand bring the membrane of the electrode down perpendicular to the paper and with a slight swirling motion gently polish the tip of the electrode against the surface of the polishing paper...

Page 17: ...Electrode Life A lead electrode will last six months in normal laboratory use On line measurements might shorten operational lifetime to several months In time the response time will increase and the...

Page 18: ...t interfere with the electrode s response to lead ions The reference electrode must also be considered When two solutions of different composition are brought into contact with one another liquid junc...

Page 19: ...cted substitute another lead ion electrode that is known to be in good working order for the questionable electrode If the problem persists and you are using an electrode pair try the same routine wit...

Page 20: ...e analysis method is clearly understood and is compatible with the sample Refer to the instruction manual again Reread sections on GENERAL PREPARATION and ELECTRODE CHARACTERISTICS If trouble still pe...

Page 21: ...with shorting strap Unstable Readings readings air bubble on membrane remove bubble by re dipping electrode continuously or rapidly changing electrode exposed soak electrode in lead standard to interf...

Page 22: ...correct scaling plot millivolts on the linear axis On but calibration of semi log paper the log axis be sure concentration curve is good numbers within each decade are increasing with increasing conce...

Page 23: ...us solutions only no organic solvents Size 110 mm length 12 mm diameter 1 m cable length Storage Store in lead solution ORDERING INFORMATION CODE NO DESCRIPTION EC PB 03 Lead Ion Electrode epoxy body...

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