User Reset
Reset the CTS calibration to the user’s default settings by using the user reset function.
Temperature user calibration is not affected by the user reset function.
1. Press MENU/
v
to enter setup window. Scroll down by pressing MENU/
v
to select Reset.
Press HOLD/
to select Reset. The display shows User Reset and Factory Reset.
2. Press HOLD/
to select User Reset.
3. The display automatically shows No and Yes. Scroll down by pressing MENU/
v
to toggle between No and Yes.
4. Press HOLD/
to confirm either No or Yes. Display shows User Reset option with a .
Factory Reset
Reset the CTSTestr to the factory default settings by using the factory reset function.
1. Press MENU/
v
to enter setup window. Scroll down by pressing the MENU/
v
to select Reset. Press HOLD/
to select Reset. The display shows User Reset and
Factory Reset.
2. Scroll down by pressing MENU/
v
to toggle between the resets. Press HOLD/
to select Factory Reset.
3. The display automatically shows No and Yes. Scroll down by pressing MENU/
v
to toggle between No and Yes.
4. Press HOLD/
to confirm either No or Yes. The display shows the Factory Reset
option with a .
Measure
Settings
Temp Set
Factory Reset
hold
No
Yes
menu
hold
User Reset
Reset
Measure
Settings
Temp Set
User Reset
hold
hold
No
Yes
menu
hold
Reset
Factory Reset
Specifications
CTSTestr 50
Conductivity
Conductivity range
0.0 to 200.0 μS, 200 to 2000 μS, 2.00 to 20.00 mS
Resolution
0.1 μS, 1 μS, 0.01 mS
Relative accuracy
±1% full scale
Normalization temperature
25.0ºC (77ºF)
Temperature co-efficient
0.0% to 10.0%
Calibration points
Up to 3 points
TDS
TDS range
0.0 to 100.0 ppm, 100 to 1000 ppm, 0.10 to 10.00 ppt (TDS Factor 0.5)
Resolution
0.1 ppm, 1 ppm, 0.01 ppt
Relative accuracy
±1% full scale
Calibration points
Up to 3 points
TDS factor
0.40 to 1.00 (selectable)
Salinity
Salinity range
0.00 to 10.00 ppt
Resolution
0.10 ppt
Relative accuracy
±1% full scale
Calibration points
1
Temperature
Temperature range
0 to 60°C (32.0 to 140.0°F)
Temperature resolution
0.1°C / 0.1°F
Temperature accuracy
From 0 to 50ºC (±0.5ºC / ±0.9ºF + 1 LSD);
from 50 to 60ºC (±1.0ºC / ±1.8ºF + 1 LSD)
Temperature compensation
Yes (Automatic Temperature Compensation)
General
Display
Graphics, dot matrix 80 x 100 pixel
Auto off
8.5 minutes (from last key press)
Reset
User / Factory
Power requirement
Four AAA 1.5 V batteries
Battey life
>150 hours
Water proofing
IP67
Environmental operating conditions
Ambient operating
temperature
5 to 45°C / 41 to 113°F
Relative humidity
5% to 85% noncondensing
Storage temperature
–20 to 60°C / –4 to 140°F
Storage humidity
5% to 85% noncondensing
Ordering Code
Product Description
35634-55
CTSTestr 50P pin-style pocket tester with case, lanyard, and batteries
35634-65
CTSTestr 50C cup-style pocket tester with case, lanyard, and batteries
35634-57
Replacement sensor module for CTSTestr 50P pin-style tester
35634-07
Replacement sensor module for CTSTestr 50C cup-style tester
35634-09
Replacement sensor cap
09376-00
Replacement alkaline batteries; AAA, 1.5 V. Pack of 12
17101-45
NIST-traceable calibration with data for pocket testers
Accessories
HOLD Function
This feature helps to freeze the display for a delayed observation.
1. Press HOLD/
button to freeze
2. Press HOLD/
again to release
measurement.
measurement.
1065O100_MAN_35634-55,-65
August, 2017
www.4oakton.com
Replacing the Batteries
The CTSTestr 50 Pocket Tester uses four
AAA 1.5 V batteries.
1. To remove the battery cover, see Figure 1.
Clear the front catch and then the back
catch, before sliding the cover off.
2. To remove the battery plate, push the
center tab towards the front of the tester
as shown in Figure 2. Once unlocked,
remove the plate to access the batteries.
3. Invert the tester upside down to remove
the batteries. Each side uses two
AAA batteries. Orient each battery with
positive terminal facing downward.
4. To lock the battery plate, align the small
tabs (Figure 3) into the guide ribs on
the housing and then press down.
See Figure 4.
Fig. 3: Align tabs
Fig. 4: Push down to lock
Fig. 5: Battery plate unlocked
Fig. 6: Battery plate locked
Fig. 2: Push to unlock
Fig. 1: Removing battery cover
Sensor Replacement
Replace the sensor module at the fraction of the cost of a new tester. When the
tester fails to calibrate or gives fluctuating readings in calibration standards, you
need to change the electrode.
1. With dry hands, grip the ring with sensor facing you. Twist the ring counter-
clockwise. Save the ring for later use.
2. Pull the old sensor module away from the tester.
3. Align the four tabs on the new module so that they match the four slots on
the tester.
4. Gently push the module onto the slots to sit it in position. Push the smaller
O-ring fully onto the new sensor module. Push the other O-ring over the
module and thread it into place by firmly twisting clockwise.
Note: It is necessary that you recalibrate your tester prior to measurement after
a sensor replacement.
Self-Diagnostic Messages
Batteries are weak and need replacement soon.
stable error
Appears when calibration is attempted but the reading is not yet stable. Wait for
the reading to stabilize or manually confirm the calibration by pressing enter.
over range
The reading is above the measuring range of tester.
Sensor Maintenance
1. Always keep the sensors electrodes clean. Rinse the electrodes with
deionized water and wipe them dry with clean cloth before storing with its
protective cap. For cup type electrodes, remove the white plastic cup and
insert to thoroughly clean viscous solutions. Never scratch electrodes with
a hard substance.
2. For better performance, soak the electrode in alcohol for 10 to 15 minutes and
rinse with de-ionized water before starting any measurement process. This is
to remove dirt and oil stains on the electrode which may affect the accuracy
of the measurements.
COND
μs/cm
820
23.5 °C
μs/cm
820
23.5 °C
COND
Press Hold
to release
COND
μs/cm
820
23.5 °C
hold
Press Hold
to release
Warranty
This instrument is supplied with a warranty against manufacturing defects for
a period of one year from the date of purchase.
Return of Items
Authorization must be obtained from your distributor before returning items
for any reason. When applying for authorization, please include information
regarding the reason the item(s) are to be returned.
We reserve the right to make improvements in design, construction and
appearance of products without notice. Prices are subject to change without
notice.
Key Info
Scroll
Accept
EXIT
MENU
HOLD
CAL
Key Info
Scroll
Accept
EXIT
MENU
HOLD
CAL
COND
μs/cm
820
23.5 °C
1065O100_MAN_35634-55,-65.indd 2
9/5/2017 3:07:29 PM
