INSTRUCTION MANUAL
DOT - 466
DIGITAL CONDUCTIVITY METER
A product of:
dot technologies
25, 2nd Floor, Victoria Road,
Bangalore-560047, Fax:08025542753
Phone:080 25549344 / 09844010308
Email :
www.dottechinstrument.com
DIGITAL CONDUCTIVITY METER dot 466Digital Conductivity meter dot 466 is a compact portable precision instrument measures conductivity displays values directly.
APPLICATION: For measurement of salt content in natural water, drinking water, treated water, waste water, brine solutions, soluble salts in soiletc.
TECHNICALSPECIFICATIONS:
RANGE / 200 µMhos/cm to 1000 m Mhos/cm in 5 ranges
MEASURING FREQUENCY / 1000 Hz
CELL CONSTANT / 0.4 to 1.5 adjustable
RESOLUTION / 0.1µMhos/cm
ACCURACY / +/- 1 % +/- 4 digits
GENERAL SPECIFICATIONS:
DISPLAY / 3 1/2 digits LED 0.5" height red color
OVER RANGE INDICATION / Display indicates 1
FUNCTION SELECTOR / Check / cond / cell constant
TEMP. CO. / 100 PPm / °C
All the accuracy are specified at / 25°C, 50% RH.
POWER REQUIREMENT / 230 +/-10% VAC, 50 Hz, 1~
CABINET SIZE / 70 mm (H) x 215 mm (W) x 280 mm (D).
WEIGHT / 2.5 Kgs. Approx
The instrument is supplied with test leads, mains cord, spare fuse, and comprehensive operating manual.
INTRODUCTION:
DOT - 466 is a 3 1/2 digit Conductivity Meter spanning a range of 1 µMhos/cm to 1000 m Mhos/cm in 5 ranges, uses latest MOS - LSI technology.
APPLICATIONS:
For measurement of salt content in natural water, drinking water, treated water, wastewater, brine solutions, soluble salts in soiletc.
CONTROLS, CONNECTORS, INDICATORS:
POWER ON : Turns power on / off
DISPLAY : Indicates the conductivity value of any aqueous solution.
FUNCTION : CHECK position the display reads 1.000 if not adjust with rear
cal control knob.
COND position the unit measures conductivity of the solution under
Test.
CELL CONST position the display reads conductivity cell constant
and can be adjusted by cell constant knob.
CELL CONSTANT : cell constant can be adjusted by this knob.
RANGE : For selecting desired range for best resolution.
Selection of lowest possible range recommended.
TEMP “C : To compensate temperature of solution.
REAR CONTROLS
LINE VOLTAGE
RECEPTACLE : For powering the instrument.
FUSE : Fuse cartridge is placed below the line voltage socket with extra fuse.
CAL CONTROL : To adjust calibration.
CELL INPUT : Connect the conductivity cell banana terminals red to red &
black to black terminal
INSTALLATION:
· Check instrument physically, if damaged return back to factory within 15 days of receipt.
· Connect power cord to line voltage receptacle. Press Power ON switch to Switch ON power
· DISPLAY indicates value or 1(means over range).
· Wash the conductivity cell with distilled water.
· Connect conductivity cell to rear terminal Black-to-Black terminal and red-to-red terminals.
· Select function switch to “check” position display shall read 1.000 if not so, set cal control knob ( at rear panel) for display reading of 1.000
· Select function switch to “cell const.” Position set the required cell constant by cell constant knob to 1.000 or the cell constant.
· Select function switch to “cond.” Position now the instrument reads conductivity of the solution under test.
· Set temperature knob to room temperature or the temperature of the solution under test.
· Dip conductivity cell in the solution under test.
· The display reads the conductivity of the solution.
· Select appropriate range by selecting range selector to get best resolution.
· Reading should be noted after 15 minutes warm up time from Power ON.
CELL CONSTANT VARIFICATION:
Cell constant can be verified by following procedure:
· Select function switch to “check” position display shall read 1.000 if not so, set cal control knob (at rear panel) for display reading of 1.000
· Dip conductivity cell in a solution of known value.
· Set temperature knob to room temperature or the temperature of the solution under test.
· Select function switch to “cond.” Position and range switch to appropriate range
· Adjust the cell constant knob so that display reads the known value of the solution.
· Select the function to cell const.
· The display indicates cell constant.
SAFETY REGULATION:
· External voltage should not be applied to test terminals.
· Three-pin cord must be used with grounding terminals for line voltage.
STANDARD CONDUCTIVITY REAGENTS
Dissolve 0.5232 g potassium chloride, dried at 1800 C for 1 hour in demineralised water and dilute to 1000 ml. The distilled water used for preparing standard solutions should have a very low conductivity. The specific conductance of this solution at 250 C is 1000 ms/cm. Alternatively, dissolve 0.7456 g of anhydrous potassium chloride, dried at 1800 C for 1 hour in distilled water and make up to 1000 ml at 250 C. The specific conductance of this solution at 250 C is 1408 ms/cm.
CARE OF CONDUCTIVITY CELL
After the use, the conductivity cell must be thoroughly washed or immersed in the distilled water. The cell may be washed by cleaning it in 90% detergent solution and scrubing it with very fine brush. For more tenacious deposits, 2% solution of Hydrochloric acid (HCI) may be used. Utmost care must be kept so that the ‘ Platinization’ of the electrode is not damaged.
WARNING : PLEASE DO NOT FINGER THE CELL ELECTRODES
PRECAUTIONS
1. Conductivity cell may be cleaned by using warm 50% detergent solution
2. Platinum plates of the conductivity cell must be completely dipped in supermatant
Solution while taking readings.
3. Check the cell constant as frequently as possible because deposition of film on the
Plates effect cell constant
4. Rinse the cell in demineralized water
5. Do not finger the cell electrodes.
The conductivity of most electrolyte solutions increase with rise in temperature. Weak aqueous solutions generally have temp. co-efficient of conductance nearly 2% C. Acid and Alkaline solutions of moderate strength in general exhibit a temperature co-efficient of 1.7% per 0 C.
FAULT FINDING GUIDE
FAULT FINDING TUIDE
The following table may be useful in correcting malfunctions and avoiding simple pitfalls.
------
FAULTS REMEDY
------
1. NO DISPLAY
(a) A.C. supply is no present Check A.C. supply
(b) Fuse at the back open circuit Replace fuse (100 mA)
2. INACCURATE READINGS
Contaminated buffer solution Prepare a fresh solution
3. DISPLAY FLICKERING
(a) Poor earthing Connect an efficient earth
(b) Severe Interference through the Eliminate cause of disturbance
the electricity supply from switching or move instrument to another
devices etc., or R.F. radiations from location or connect to a different
similar devices circuit.
If the fault still exists, please refer to the nearest distributor for repairs by the Engineer
Of the Company
Note : DO NOT PLAY WITH THE INTERNAL CIRCUITARY OF THE INSTRUMENT.
WARRANTY STANDS ONLY IF THE SEAL IS INTACT.
MAINTENANCE & WARRANTY
ROUTINE MAINTENANCE
The design of the instrument is such that no routine maintenance is required to be carried out by the customer.
As with any high impedence instrument, it should not be exposed unnecessarily to dirty atmosphere and it should be covered by a plastic dust cover when not in use.
WARNING
VOLTAGE DANGEROUS TO HUMAN LIFE ARE PRESENT IN THIS INSTRUMENT. DISCONNECT FROM POWER SUPPLY BEFORE REMOVING THE INSTRUMENT COVER.
6