Extech Instruments pH300 User manual

User's Guide
Digital pH Meter
Model pH300
www.burntec.com

pH300 V1.0 7/09
2
Introduction
Congratulations on your purchase of the Extech pH meter. For best results, please read
the entire manual before use.
The pH300 meter measures pH, mV, and temperature parameters. The built-in
microprocessor provides automatic calibration, automatic temperature compensation,
data storage, and self-diagnostics. The meter can recognize up to 13 types of pH
standard buffer solutions.
The meter’s digital filter improves measurement speed and accuracy.
Two special modes (ammonia and purified water) are provided.
The meter offers a backlit LCD display and is dust-proof and water-proof, meeting the
IP57 rating
This meter is shipped fully tested and calibrated and, with proper use, will provide years
of reliable service.
Supplied Equipment List
•pH300 Meter
•pH / ATC (Automatic Temperature Compensation) Electrode
•Standard buffer solutions (4.00pH, 7.00pH, and 10.01pH) / 50ml
•Screwdriver (for removing battery compartment)
•Batteries (2 x ’AA’ 1.5V)
•User’s Guide
•Carrying Case
www.burntec.com

pH300 V1.0 7/09
3
Meter Description
1. LCD Display (detailed in section below)
2. Rubber protective jacket (remove to access the rear battery compartment)
3. Keypad (detailed in section below)
4. Electrode connection jack
5. Electrode plug
6. Electrode measuring bulb
7. Electrode body
8. Electrode cable
Display Description
1. Parameter Mode icon
2. Measurement reading
3. 888 (Stored data serial number),
M+ (measurement to be stored
icon), RM (reading to be recalled
icon)
4. Unit of measure
5. Temperature reading
6. Stable measurement icon
7. Calibration icons
8. Low battery icon
www.burntec.com

pH300 V1.0 7/09
4
Keypad Description
The meter has five (5) front panel function keys:
ON/OFF Power Key
Calibration Key:
a) When taking a measurement, press this key to enter the calibration mode
b) When in the programming mode, press this key to change the displayed
number or the ON/OFF state
Function Key
a) Press momentarily (< 1.5 seconds) to toggle between the two measurement
parameters pH and mV
b) Press and hold for at least 2 seconds to enter the P1 programming parameter.
Subsequent presses will scroll through the remaining parameters P2, P3…
Backlight and ENTER Key
a) In the measurement mode, momentary presses toggle the backlight on and off
b) When in the programming or calibration mode, press to ENTER data
MEMORY STORE and RECALL Key
a) In the measurement mode, momentary presses store the displayed readings.
Press and hold for at least 2 seconds to recall a saved reading
b) In the programming mode, press to change the displayed number or the
ON/OFF state
Store, Recall, and Clear Datalogger Memory
STORE Readings
The meter can store up to 100 pH and 100 mV readings for a total of 200 data points. To
store a reading, wait until the reading stabilizes (the smiling face icon appears when the
reading stabilizes). Press the M+/RM key momentarily to store a reading. The M+ icon
appears and the data point serial number increments.
RECALL Readings
In the measurement mode, press the M+/RM key to recall the most recently stored
reading. RM and the data point serial number for the displayed reading will appear on the
LCD. The measurement information will appear on the lower right hand side of the LCD.
Use the CAL or M+/RM buttons to scroll the remaining stored readings. Press the ENTER
key to return to the normal measurement mode.
CLEAR Readings
From the RECALL mode, press and hold the ENTER key for at least five (5) seconds. The
LCD display will show ‘CLR’ indicating that all of the stored readings have been erased.
The unit will automatically return to the normal measurement mode after approximately 2
seconds.
www.burntec.com

pH300 V1.0 7/09
5
pH Measurement Mode
Preparation for Measurement
1. Turn the meter ON using the power key
2. Press the MODE key momentarily to switch to the pH mode, if necessary
3. Unscrew the protective cap on the probe jack located on the bottom of the meter (store
the protective cap in the carrying case for later use)
4. Carefully connect the pH probe to the meter’s probe jack. The probe can only be
inserted in one orientation. Once it is firmly connected, screw the probe collar onto the
meter to secure the probe.
3-Point Calibration (7.00pH, 4.00pH and 10.01pH)
Note: Calibrate the unit once per day for best results.
1. Press the CAL key to enter the Calibration mode. The meter’s display will show a
blinking ‘Cl’
2. Rinse the probe in distilled water, allow it to dry, and submerge it into a pH 7.00 buffer
solution. Stir the solution briefly and allow it to stay in the buffer solution until a stable
reading is reached
3. Press CAL again and the display will show a blinking ‘7.00’
4. This portion of the calibration procedure is complete when the display stops blinking
and shows the ‘C2’ icon. The unit will automatically switch to the second point of the
calibration
5. Rinse the probe in distilled water again, allow it to dry, and submerge it into a pH 4.00
buffer solution. Stir the solution briefly and allow it to stay in the buffer solution until a
stable reading is reached
6. Press CAL again and the display will show a blinking ‘4.00’
7. This portion of the calibration procedure is complete when the display stops blinking
and shows the ‘C3’ icon. The unit will automatically switch to the third point of the
calibration
8. Rinse the probe in distilled water again, allow it to dry, and submerge it into a pH 10.01
buffer solution. Stir the solution briefly and allow it to stay in the buffer solution until a
stable reading is reached
9. Press CAL again and the display will show a blinking ‘10.01’
10. After the display stabilizes the 3-point calibration icon will appear
1-Point and 2-Point Calibration
Note that the user can calibrate one or two points only, if the expected measurement is
known.
For example, if the expeced pH is 4pH, it is acceptable to perform only a 1-Point
Calibration (4pH). If the expected measurement is between 4.00pH and 7.00pH, the user
can perform a 2-Point Calibration (4.00 and 7.00pH), and so on.
For a 4pH calibration, only the circled Lwill appear on the LCD. For a 7.00pH, only the
circled Mwill appear on the LCD. For a 10.01pH Calibration, only the circled Hwill appear
(Low, Medium, and High).
For all other applications, a 3-Point Calibration is recommended. Always perform a 3-Point
Calibration on new probes and probes that have been in use for long periods. This
maximizes measurement slope linearity.
www.burntec.com