ORPTestr
®
5 Pocket Tester
Features
• Large easy-to-read LCD with 3-color backlight
• Replaceable single-junction sensor saves you money
• Stability and battery status icons
• Auto power-off function conserves battery life
• IP67 waterproof rating
Operating Manual
Thank you for purchasing the Oakton
®
ORPTestr
®
5 Pocket Tester.
Please carefully read this operating manual before using the product
to obtain an accurate and reliable test result and avoid unnecessary
damage to the tester or probe.
ORP Calibration
1. Clean electrode in distilled water and dry it.
2. Pour a small amount of 222 mV ORP stan-
dard solution (SKU 80055-90, 500-mL bottle)
into the calibration bottle.
3. Short press /MEAS key to turn the meter
on. Long press CAL/
key to enter calibra-
tion mode. If you need to exit calibration
mode, short press /MEAS key.
4. Dip electrode in the ORP standard solution
(Zobell’s solution), stir gently, and allow it
to stand still in the calibration solution until
a stable reading is reached. When measure-
ment stability icon (
) appears and remains
on the screen (see Fig. 1), press MODE/
key to adjust the calibration value according
to the table below (also on the buffer bottle’s label).
ORP Standard Buffer Solution Calibration Reference Table
Temperature (ºC)
mV
Temperature (ºC)
mV
10
242
30
215
15
235
35
209
20
227
38
205
25
222
40
201
For example, if the temperature is around 25ºC, then adjust the cali-
bration value to 222 mV. If the temperature is around 20ºC, then
adjust the calibration value to 227 mV. Short press CAL/
key to
complete the calibration.
ORP Measurement
Press /MEAS key to power on, clean the probe in distilled water,
and gently dry it. Place the probe in the tested solution and stir
gently and let it stand still. Read the measurement after the stability
icon (
) appears and remains on.
Notes
Usually there’s no need to calibrate for ORP testing. When not used
for a long time, users can test the unit in 222 mV ORP standard buf-
fer. If the error is large, recalibrate according to the steps above.
Cleaning and Activating the ORP Probes
After long-time use, the surface of the platinum sensor can be con-
taminated and cause inaccuracy and slow response time. If that hap-
pens, the followed methods can be adopted to clean and activate:
A. For contamination caused by inorganic substances, dip the
probe into 0.1 mol/L dilute hydrochloric acid for 30 minutes.
Clean it with distilled water, soak in KCL storage solution
(SKU 00653-04) for 6 hours, and then it will be ready for use.
B. For contamination caused by organic substances and oiliness,
clean the platinum surface with dishwashing liquid and wash
with distilled water. Soak for 6 hours in storage solution
(SKU 00653-04) and then it will be ready for use.
C. If the platinum surface is so severely contaminated that an
oxide film forms, use toothpaste to clean the platinum surface,
and then wash it with distilled water. The probe will be ready
for use again after 6 hours of soaking in the storage solution
(SKU 00653-04).
Setting the Parameters
When tester is off, long press /MEAS key to enter parameter setting
mode. Short press MODE/
key to switch from P1 to P2…P6. Short
press CAL/
key and parameter will flash, then short press MODE/
key to choose desired parameter. Short press CAL/
key to confirm
selection. Long press /MEAS key to exit parameter setting mode.
Symbol
Menu setting
Selection
Factory default
P1
Set low measurement alarm
–1000 to +1000 mV
–1000
P2
Set high measurement alarm –1000 to +1000 mV
1000
P3
Select Automatic Lock (HOLD)
Off – On
Off
P4
Select backlight
Off – 1 – On
1 (1-min auto-off)
P5
Select temperature unit
°C – °F
°C
P6
Restore to factory default
No – Yes
No
A. High and Low Measurement Heads-Up Examples (P1 and P2)
Heads-up when measured value
≤
120 mV:
Preset low value = 120
mV, highest value = 1000 mV, when measured value is
≤
120 mV (sta-
bility icon (
) displays on LCD) the red backlight appears on display.
Heads-up when measured value
≥
150 mV:
Preset high value = 150
mV, lowest value = –1000 mV, when measured value is
≥
150 mV (sta-
bility icon (
) displays on LCD) the red backlight appears on display.
Heads-up when measured value in range of 120 mV and 150 mV:
Preset low value = 120 mV, highest value = 150 mV, when the
measured value is <120 mV or >150 mV (stability icon (
) displays
on LCD) the red backlight appears on display.
B. Automatic Lock (P3)
Select “On” to activate auto lock function. When reading is stable for
more than 10 seconds, the tester will lock the value automatically,
and “
HOLD
” icon will appear on the bottom left of the screen. Press
CAL/
key to cancel HOLD on reading.
C. Backlight (P4)
Select “Off” to turn off backlight function, “On” to turn on backlight
function, or “1” to have backlight last for 1 minute.
D. Temperature Unit (P5)
Select °C or °F; the factory default is °C.
E. Factory Default Setting (P6)
Select “Yes” to recover tester calibration to theoretical value (pH
value in zero potential is 7.00, slope is 100%), parameter setting
return to initial value. This function can be used when instrument
does not work well in calibration or measurement. Calibrate and
measure again after resetting the unit to factory default status.
220
25.8
mV
ORP
☺
☺
°c
Figure 1
Keypad Functions
Short press
= <2 seconds
Long press
= >2 seconds
MEAS
1. Short press to turn on the tester and long press to
turn off the tester.
2. When turned off, long press to enter parameter setting mode.
3. In measurement mode, short press to turn on backlight.
MODE
1. In calibration mode, short press to change calibration
value (unidirectional).
2. In mode setting, short press to change parameter
(unidirectional).
CAL
<
1. Long press to enter calibration mode.
2. In calibration mode, short press to confirm calibration.
3. When measured value is locked (HOLD icon), short press
to unlock.
Preparation Before Use
1. Pour certain amount of storage solution (KCl) into the probe
cap, soak the probe for 3 to 5 minutes to activate the sensor
(if frequently used, there is no need to soak).
2. The soaking solution is 3M KCl solution; preferably Oakton
Electrode Storage Solution (SKU 00653-04). Users can also make
it themselves by dissolving 25 g KCl in 100 ml of distilled water.
