Drawell Jenco Vision Plus EC331 User manual

Operation
Manual
MODEL EC331
Microcomputer Based
Conductivity /Resistivity
& Temperature Pocket
Meter
EC331

1
CONTENTS
INITIAL INSPECTION AND ASSEMBLY ...................2
VISIONPLUS EC331 OVERVIEW.................................2
A. Meter Description..................................................2
B. LCD Display ..........................................................2
OPERATION MODES AND KEYPAD OPERATIONS...3
A. Operation Modes......................................................3
B. Keypad Operations................................................3
BEFORE YOUR FIRST USE ..........................…………4
A. Insert Batteries .....................................................4
B. Soak the Electrode.... ............................................4
C. Preparing Standard Solutions.................................4
D. Setup and Calibrate the Electrode and Meter...........5
USING VISIONPLUS EC331.........................................5
A. Power on/off .........................................................5
B. Calibrate Conductivity............................................5
C. Measure ...............................................................5
D. Hold Data .............................................................5
REPLACE ELECTRODE…...........................................6
REPLACE THE OLD BATTERIES................................6
ERROR DISPLAYS AND TROUBLESHOOTING …....7
SPECIFICATIONS ........................................................8
WARRANTY .................................................................9

2
INITIAL INSPECTION AND ASSEMBLY
Carefully unpack the instrument and accessories. Inspect for
damages made in shipment. If any damage is found, notify your
Drawell representative immediately. All packing materials should
be saved until satisfactory operation is confirmed.
VISIONPLUS EC 331 OVERVIEW
A. Meter Description
1. Battery cover
2. LCD screen
3. Keypad
4. Electrode collar
5. Electrode & ATC assembly
(Electrode cap is not shown.)
B. LCD Display
1
2
3
4
5
6
7
8
9
1. LOW BATTERY indicator
2. CALIBRATION mode indicator
3. MEASURE mode indicator
4. HOLD mode indicator
Hold
Cal M ode
R
EC 331
VisionPlus
1
2
3
4
5

3
5. CONDUCTIVITY/RESISTIVITY mode indicator
6. CONDUCTIVITY/RESISTIVITY unit indicator
7. CONDUCTIVITY/ RESISTIVITY reading
8. TEMPERATURE reading
9. TEMPERATURE unit indicator
OPERATION MODES AND KEYPAD OPERATIONS
A. Operation Modes
VisionPlus EC331 meter has 3 operation modes:
1. Measure Mode. Measure Mode is used to make all
conductivity or resistivity and temperature measurements.
2. Calibration Mode. Calibration Mode is used to perform one
point calibration.
3. Hold Mode. Hold Mode is used to display the locked
reading for increased ease of use.
B. Keypad Operations
Key
Operation
Mode
Duration
Function
Hold
Measure
0 second
Holds current
measurement reading.
Press again to resume
measuring.
Hold
0 second
Returns to Measure Mode.
Measure
5 second
. Erases all stored data.
Cal
Measure
0 second
Enters Calibration Mode.
On/Off
All
0 second
Turns meter on/off.
Mode
Measure
0 second
Selects display mode:
Conductivity (℃),
Conductivity (℉),
Resistivity(℃) and
Resistivity(℉).

4
BEFORE YOUR FIRST USE
A. Insert Batteries
1. Remove the battery cover
at the top of the unit.
2. Insert the set of batteries
(included) ensuring correct
polarities.
3. Securely replace battery
cover.
B. Soak the Electrode
1. Remove the electrode cap covering the VisionPlus EC331
meter.
2. Soak the electrode in distilled water for 10 minutes before
first use or after storage.
C. Preparing Standard Solutions
Suitable conductivity standards are available commercially or the
user can prepare them using research grade reagents.
Here is the 147.0uS standard solution the user can prepare to
calibrate the probe of the model EC331.
Standard solution of 147.0uS at 25℃: Accurately measure 100mL
of the 1413uS conductivity standard solution. Dilute with 900ml of
distilled water.
(Standard solution of 1413uS at 25 ℃: Accurately weight out
0.746 grams of research grade dried Potassium Chloride (KCL).
Dissolve in 1000ml of distilled water.)
[Note: You can store the remaining solution in a plastic container
for one week but the air space between the cap and the solution
must be kept to an absolute minimum. Storing the excess solution
below 4℃can increase the storage life. If you have any doubt of
the accuracy of the stored solution, a fresh batch should be
prepared.]
12

5
D. Setup and Calibrate the Electrode and Meter
VisionPlus EC331 must be setup and calibrated before your
first use. Please follow the instructions detailed in section
USING VISIONPLUS EC331 6.
USING VISIONPLUS EC331
A. Power On/Off
Press “On/Off ” key to turn the unit on. If the unit is running then
you can press ”On/Off “ key to turn the unit off. The unit will
automatically turn off after 10 minutes of no key activity.
[Note: The unit will not automatically shut off if it is still immersed
in solution even after 10 minute of no key activity.]
B. Calibrate Conductivity
1. Rinse the electrode & ATC assembly in distilled water and
immerse them in the standard solution of 147uS. The
temperature displayed is the solution temperature.
2. Press “Cal” key to initiate calibration. The “CAL” icon will
appear when the main display shows “147.0”. Calibration
is now complete. The “MEAS” icon will appear. The unit is
now ready to measure.
C. Measure
In the “Measure Mode”, dip the meter into the test solution.
Measuring for Conductivity (℃) commences. Press “Mode” key to
select: Conductivity( ℃), Conductivity( ℉), Resistivity ( ℃) and
Resistivity (℉).
[Note: If the “CAL” icon does not appear during measuring, it
means the unit has not been calibrated. Repeat the calibration
procedure.]
D. Hold Data
1. When the Conductivity or Resistivity reading is stable,
press “Hold” key once to lock the reading.
2. Press “Hold” key again to unlock reading and the unit will

6
return to “Measure Mode”. The unit is now ready for
another measurement.
REPLACE ELECTRODE
1. Unscrew the electrode collar to remove the electrode &
ATC assembly as shown in the right figure.
2. Remove the old electrode
from the meter.
3. Insert a new electrode,
make sure the electrode fit
back into the meter
correctly.
4. Screw back the electrode collar.
5. Soak the electrode in distilled water for 10 minutes and
recalibrate the EC331 following the instructions detailed in
section USING VISIONPLUS EC331.
REPLACE THE OLD BATTERIES
Replace the battery when the blinking low battery indicator “ ”
appears on the upper left corner of the LCD screen. The instrument
can operate within specifications for approximately 2~3 hours after
low battery indicator appears.
1. Take off the battery cover.
2. Remove all of the old batteries and insert a new set of
batteries ensuring the polarities are correct.
[Note: Calibration of the unit is required after replacement of
batteries.]

7
ERROR DISPLAYS AND TROUBLESHOOTING
Conductivity
Display
ATC
Display
y
DISPLAY
Mode
Possible cause(s)
[Action(s)]
"OVER"
"OVER"
Measure
Temperature >99.5
°C range.
[Bring solution to a
lower temperature.]
[Replace electrode &
ATC assembly .]
"OVER"
"udr"
Measure
Temperature
<0.0°C range.
[Bring solution to a
higher
temperature.]
[Replace electrode &
ATC assembly .]
"OVER"
60.0 ~ 99.5°C
Measure
Temperature >60.0
°C, over the
temperature
compensation
range.
[Bring solution to a
lower temperature.]
"OVER"
0.0 ~ 60.0°C
Measure
The conductivity
value of the test
solution is beyond
200uS.
[Sample cannot be
tested or replace
electrode & ATC
assembly.]
"ERR"
/
Calibration
a. Temperature
exceed 0 ~
60.0°C
Temperature
compensation
b. Correction of
slope beyond
50%.
[Bring solution to a
lower temperature.]
[Use a new
standard solution.]
[Replace electrode
& ATC assembly.]

8
SPECIFICATIONS
Conductivity
Range
Resolution
Accuracy
0.1 to 199.9uS
0.1uS (0.0~ 50.0uS), 0.5uS
(50.0~ 100.0uS) and 1.0uS
typical (100.0~199.0uS)
±1% FS
Resistivity
Range
Resolution
Accuracy
1.0~20.0MΩ
0.1MΩ
±1% FS
Temperature
Range
Resolution
Accuracy
0.0 to 99.5 °C
32 to 212 °F
0.5 °C
1 °F
±0.5 °C
±1 °F
Conductivity
Temperature compensation
Temperature Coefficient
Reference temperature
AUTO 0.0°C to 60.0 °C
1.91%/°C
25°C
Temperature
Temperature sensor Thermistor, 10 k Ω at 25°C
Temperature unit °C and °F
General
Power: LR44 x 4
Battery life: >100 Hours
Ambient temperature range 0.0 to 50.0 °C
Case IP67 water-tight case
Weight 105 g

9
WARRANTY
Drawell warrants this product to be free from significant
deviations in material and workmanship for a period of 1 year
from date of purchase. If repair or adjustment is necessary and
has not been the result of abuse or misuse, within the year
period, please return-freight-prepaid and the correction of the
defect will be made free of charge. If you purchased the item
from our Drawell distributors and it is under warranty, please
contact them to notify us of the situation. Drawell Service
Department alone will determine if the product problem is due to
deviations or customer misuse.
Out-of-warranty products will be repaired on a charge basis.
RETURN OF ITEMS
Authorization must be obtained from one of our representatives
before returning items for any reason. When applying for
authorization, have the model and serial number handy,
including data regarding the reason for return. For your
protection, items must be carefully packed to prevent damage in
shipment and insured against possible damage or loss. Drawell
will not be responsible for damage resulting from careless or
insufficient packing. A fee will be charged on all authorized
returns.
NOTE: Drawell reserves the right to make improvements in
design, construction and appearance of our products without
notice.

10
Drawell International Technology Limited
Shanghai Drawell Scientific Instrument Co.,Ltd
Add : Suite 1506,Lane581 XiuChuan Rd.,PuDong New
Area,Shanghai,China
Tel: [phone]
Fax: [phone]
Web : www.drawell.com.cn
Email : sales0[email protected].cn