YSI 63 User manual

YSI Model 63
Handheld pH,
Conductivity,
Salinity and
Temperature
System
Operations
Manual

i
Table of Contents
1. Introduction................................................................................................................1
2. Preparing the Meter...................................................................................................2
2.1 Unpacking ...........................................................................................................................2
2.2 Warranty Card.....................................................................................................................2
2.3 Batteries...............................................................................................................................2
2.4 Transport Chamber..............................................................................................................3
2.5 Hand Strap...........................................................................................................................3
2.6 The Meter Case ...................................................................................................................3
3. Preparing the Probe..................................................................................................4
3.1 Installing the pH Sensor......................................................................................................4
4. Operation ...................................................................................................................5
4.1 Turning The Instrument On.................................................................................................6
4.2 pH Calibration.....................................................................................................................6
4.3 Conductivity Calibration...................................................................................................11
4.4 Making Measurements......................................................................................................12
4.5 Autoranging & Range Searching ......................................................................................14
4.6 Saving Data....................................................................................................................... 14
4.7 Recalling Stored Data........................................................................................................15
4.8 Erasing Stored Data...........................................................................................................16
4.9 Display Backlight..............................................................................................................17
5. Advanced Conductivity Setup................................................................................18
5.1 Changing The Temperature Coefficient............................................................................18
5.2 Changing The Reference Temperature.............................................................................. 19
5.3 Changing Conductivity From Autoranging To Manual Ranging ..................................... 19
6. Maintenance.............................................................................................................20
6.1 pH Sensor Precautions ......................................................................................................20
6.2 pH Sensor Cleaning...........................................................................................................20
6.3 pH Sensor Storage.............................................................................................................21
6.4 Conductivity Sensor Cleaning........................................................................................... 21
7. Discussion of Measurement Errors.......................................................................22
7.1 pH Errors...........................................................................................................................22
7.2 Conductivity Errors...........................................................................................................22
8. Troubleshooting......................................................................................................24

ii
9. Principles of Operation...........................................................................................26
9.1 pH......................................................................................................................................26
9.2 Conductivity......................................................................................................................27
9.3 Salinity ..............................................................................................................................28
9.4 Temperature ......................................................................................................................28
10. Warranty and Repair .............................................................................................29
10.1 Cleaning Instructions.......................................................................................................30
10.2 Packing Instructions........................................................................................................31
11. Required Notice.....................................................................................................32
12. Accessories and Replacement Parts...................................................................33
13. Appendix A - Specifications.................................................................................34
14. Appendix B - Health and Safety............................................................................36
15. Appendix C - pH Buffer Values.............................................................................37
16. Appendix D - Temperature Correction Data........................................................38

1
1. Introduction
The YSI Model 63 Handheld pH, Conductivity, Salinity and Temperature System is a rugged,
micro-processor based, digital meter with an attached pH, conductivity and temperature probe.
The pH sensor can be easily replaced in the field.
The Model 63 has a non-detachable cable available in lengths of 10, 25, 50 or 100 feet (3, 7.6,
15.2 or 30.5 meters). The probe body has been manufactured with stainless steel to add rugged
durability and sinking weight.
The YSI Model 63 has the following features:
•Capability to measure at depths of up to 100 feet (30.5 meters)
•Microprocessor control
•Field replaceable low maintenance pH sensor
•Push-button calibration
•Simultaneous display of pH, conductivity or salinity and temperature
•Automatic temperature compensation for conductivity readings
•Autoranging
•Data storage for 50 sets of readings with on screen recall
•Waterproof case (IP65)
The Model 63’s micro-processor allows the system to be easily calibrated with the press of a few
keys. Additionally, the micro-processor performs a self-diagnostic routine each time the
instrument is turned on. The self-diagnostic routine provides useful information about the
function of the instrument and probe.
A transport chamber, built into the instrument case, provides a convenient place to store the
probe when transporting the system. The Model 63 case is waterproof (rated to IP65) allowing
operation in the rain without damage to the instrument.
The Model 63 is powered by six AA-size alkaline batteries. A new set of alkaline batteries will
provide approximately 100 hours of continuous operation. When batteries need to be replaced,
the LCD will display a “LO BAT” message.
The YSI Model 63 is designed for use in environmental, aquaculture, and industrial applications
where accurate pH, conductivity, salinity and temperature measurements are desired.

2
2. Preparing the Meter
2.1 Unpacking
When you unpack your new YSI Model 63 Handheld pH, conductivity, salinity and Temperature
System for the first time, check the packing list to make sure you have received everything you
should have. If there is anything missing or damaged, call the dealer from whom you purchased
the system. If you do not know which of our authorized dealers sold the system to you, call YSI
Customer Service at 800-765-4974 or 937-767-7241, and we'll be happy to help you.
2.2 Warranty Card
Please complete the Warranty Card and return it to YSI. This will record your purchase of this
instrument in our computer system. Once your purchase is recorded, you will receive prompt,
efficient service in the event any part of your YSI Model 63 should ever need repair.
2.3 Batteries
There are a few things you must do to prepare your YSI Model 63 for use. First, locate the six
AA-size alkaline batteries and the battery cover kit which were included. Then locate the
markings inside each of the two battery-chamber sleeves that illustrate the correct way to install
the batteries. Install the batteries are shown.
NOTE: It is very important that the batteries be installed ONLY as illustrated. The instrument
will not function and may be damaged if the batteries are installed incorrectly.
Figure 1
Attach the battery chamber cover to bottom of the instrument using the thumb screw as shown in
Figure 1. Make sure that the o-rings are in place. The battery-chamber cover is marked with the
words "OPEN" and "CLOSE."
Turn the instrument on by pressing and releasing the ON/OFF key on the front of the instrument.
The liquid crystal display (LCD) should come on. Allow a few seconds for the instrument to
complete its diagnostic routine. If the instrument does not operate, consult the chapter entitled
Troubleshooting.
Hand stra
p
Polarity marking
Thumb screw
Battery chamber
cover
O-rings

3
You may also want to take the instrument into a dark location and, with the instrument ON, hold
down the LIGHT key. The instrument back-light should illuminate the LCD so that the display
can be easily read.
2.4 Transport Chamber
The Model 63 has a convenient transport chamber built into the instrument’s side. This chamber
provides a storage area and protection for the probe while transporting the system in the field.
Insert the round sponge (provided with the Model 63) into the bottom of the chamber. Put 6-8
drops of tap water into the sponge. The wet sponge creates a humid environment for the pH
sensor to prevent it from drying out during transport in the field (up to one week). The transport
chamber is NOT intended for long term storage of the pH sensor. See 6.3 pH Sensor Storage.
Figure 2
2.5 Hand Strap
The hand strap (see Figure 1 on previous page) is designed to allow comfortable operation of the
Model 63 with minimum effort. If the hand strap is adjusted correctly, it is unlikely that the
instrument will be easily dropped or bumped from your hand.
To adjust the hand strap on the back of the meter, unsnap the vinyl cover and pull the two Velcro
strips apart. Place your hand between the meter and the strap and adjust the strap length so that
your hand is snugly held in place. Press the two Velcro strips back together and snap the vinyl
cover back into place.
2.6 The Meter Case
The meter case is sealed at the factory and is not intended to be opened, except by authorized
service technicians. Do not attempt to separate the two halves of the meter case as this may
damage the instrument, break the water-resistant seal and may void the manufacturer's
warranty.
2.7 CalibrationVessels
A plastic 100 mL graduated cylinder and a plastic container are provided with the Model 63. The
graduated cylinder provides a convenient place to calibrate the pH sensor minimizing the amount
of solution needed. The plastic container can be used as a conductivity calibration vessel or filled
with distilled water and used as a rinse vessel while in the field. See section 4.2 pH Calibration
and section 4.3 Conductivity Calibration for details.
Probe transport
chamber

4
3. Preparing the Probe
The YSI Model 63 is shipped without the pH sensor installed. The pH sensor must be installed
before using the system (see section 3.1 Installing the pH Sensor, below). The sensor is shipped
with a protective bottle filled with a mixture of pH 4 buffer and KCl solution. Do not remove the
bottle until you are ready to use the instrument. Save the bottle for long term storage of the
probe.
3.1 Installing the pH Sensor
A pH sensor is included with the Model 63. Install the pH sensor as follows:
1. Remove the sensor from its protective packing.
2. Insert the pH sensor into the probe body (be sure to align the tabs on the sensor with the slots in
probe body) and twist 1/4 turn to lock in place. See Figure 3.
NOTE: Once installed, leave the pH sensor attached to the probe until replacement is needed.
3. Carefully remove the protective bottle (containing pH 4 buffer/KCl solution) from the sensor.
Save the bottle and solution for long term (more than 1 week) storage of the sensor. Seal the
storage bottle with the cap provided.
4. Rinse the sensor tip with distilled or deionized water.
5. Calibrate the system before use. See section 4.2 pH Calibration.
Figure 3
Insert pH sensor
into probe body
Turn sensor 1/4 turn
to lock in place
Align tabs with
slots in probe
body

5
4. Operation
The following diagram is an overview of the operation of the Model 63. See the following
sections for details of operation.
Figure 4

6
4.1 TurningThe Instrument On
With the batteries installed correctly, press the ON/OFF key. The instrument will activate all
segments of the display for a few seconds, which will be followed by a self test procedure which
will last for several more seconds. The Model 63 will briefly display the cell constant of the
conductivity probe when the self test is complete. During this power on self test sequence, the
instrument’s microprocessor is verifying that the system is working properly. If the instrument
were to detect a problem, a continuous error message would be displayed. See the chapter
entitled Troubleshooting for a list of error messages.
7.23pH
24.8°C
4.2 pH Calibration
The YSI Model 63 MUST be calibrated before making pH measurements. Calibration may be
performed at 1, 2 or 3-points (at pH 7, 4 and 10, or at pH 6.86, 4.01 and 9.18). Perform a 1-point
calibration (at pH 7 or at pH 6.86) ONLY if a previous 2 or 3-point calibration has been
performed recently. In most cases, a 2-point pH calibration will be sufficient for accurate pH
measurements, but if the general range of pH in the sample is not known, a 3-point calibration
may be necessary. 3-point calibration assures accurate pH readings regardless of the pH value of
the sample. See 9.1 pH for more details.
WARNING: Calibration reagents may be hazardous to your health. Refer to Appendix B -
Health and Safety for more information.
Before calibrating the YSI Model 63, complete the procedures discussed in the Preparing
the Meter and Preparing the Probe chapters of this manual.
The user can choose from two sets of pH buffer values for 3-point calibration. The first set
consists of the standard YSI pH buffer values of pH 7 (YSI 3822), pH 4 (YSI 3821) and pH 10
(YSI 3823). The second set available is the NIST pH 6.86, 4.01 and 9.18. Note that the first
calibration point must be either pH 7 or pH 6.86. Calibration is performed as follows:
1. Turn the instrument on by pressing the ON/OFF key. Press the MODE key until pH is
displayed.
2. Rinse the probe with deionized or distilled water, then carefully dry the probe (or rinse it with
some of the pH buffer solution to be used for calibration).
3. Place 30 to 35 mL of the pH buffer you have chosen to calibrate the system with (pH 7 or
6.86) in the 100 mL graduated cylinder (provided with the Model 63). The graduated cylinder
minimizes the amount of solution needed. Immerse the probe making sure that both the pH
and temperature sensors are covered by the solution (see Figure 5 on the following page).

7
For best results:
•Calibrate as close as possible to the sample temperature.
•After storage in pH 4 buffer/KCl solution, place the pH sensor in pH 7 (6.86) buffer and
allow to acclimate before calibrating (5 to 10 minutes).
•Always give the pH and temperature sensors enough time to equilibrate with the
temperature of the buffer.
Figure 5
4. To enter the calibration menu, use two fingers to press and release both the UP ARROW and
DOWN ARROW keys at the same time. The Model 63 display will show CAL at the
bottom, STAND will be flashing and the pH reading will show 7.00 (the buffer to be used to
adjust the offset).
7.00pH
STAND CAL 24.8°C
NOTE: If you will be calibrating with pH buffers of 6.86, 4.01 and 9.18 (instead of 7, 4 and
10), press both the UP ARROW and DOWN ARROW keys again. The display will change
to 6.86.
NOTE: The Model 63 automatically accounts for the fact that the true pH of the buffers
changes with temperature, therefore, the pH values displayed during calibration will vary
with temperature. For example, pH 7 buffer at 20°C (rather than 25°C) has an actual pH of
7.02 and this number (rather than 7.00) will appear on the display when the probe is placed in
the solution. See Appendix C - pH Buffer Values.
First buffer value.
Used to adjust the offset.
Temperature sensor
pH sensor (covered by sensor guard)
Flashing

8
5. Press the ENTER key. The Model 63 display will show CAL at the bottom, STAND will
stop flashing and the pH calibration value is shown with the middle decimal point flashing.
7.00pH
STAND CAL 24.8°C
6. When the reading is stable (does not change by 0.01 pH in 10 seconds), the decimal point
will stop flashing. Press and hold the ENTER key to save the calibration point. The Model
63 will flash SAVE on the display along with OFS to indicate that the offset value has been
saved.
SAVE
OFS
7. SLOPE will now appear on the display and be flashing. This indicates that the slope is ready
to be set using a second pH buffer. The system is now calibrated at a single point. If you are
only performing a single point calibration, press the MODE key to return to normal
operation.
7.00pH
SLOPE
CAL 24.8°C
8. Rinse the probe with deionized or distilled water, then carefully dry the probe.
STOP HERE IF PERFORMING A 1-POINT CALIBRATION.
9. If you are performing a 2-point or 3-point calibration, fill a clean container with the second
value pH buffer (pH 4 or 10, or pH 4.01 or 9.18) and immerse the probe into the solution.
Make sure that the temperature sensor is immersed.
10. Press the ENTER key. The Model 63 should now show CAL at the bottom, SLOPE will
stop flashing and the pH calibration value (automatically sensed by the instrument) is shown
with one of the decimal points flashing.
Flashing
Flashes until
readin
g
is stable

9
.4.01pH
SLOPE
CAL 24.8°C
If the second pH buffer is less than the first buffer (which was used to adjust the offset; pH 7
or pH 6.86), the left decimal point will flash as shown above. If the second pH buffer is
greater than the first, the right decimal point will flash as shown below.
10.0.0pH
SLOPE
CAL 24.8°C
11. When the reading is stable (does not change by 0.01 pH in 10 seconds), the decimal point
will stop flashing. Press and hold the ENTER key to save the first SLOPE. The Model 63
will flash SAVE on the display along with SLP to indicate that the first slope value has been
saved.
SAVE
SLP
12. SLOPE will start flashing again indicating that the slope is ready to be set using a third pH
buffer.
.4.01pH
SLOPE
CAL 24.8°C
13. The system is now calibrated at two points. If you are only performing a two point
calibration, press the MODE key to return to normal operation.
14. Rinse the probe with deionized or distilled water, then carefully dry the probe.
STOP HERE IF PERFORMING A 2-POINT CALIBRATION.
Flashing
Left decimal flashes (until
reading is stable) for buffers
lower than first cal point
Right decimal flashes (until
reading is stable) for buffers
higher than first cal point
Second buffer value
Second buffer value

10
15. If you are performing a 3-point calibration, fill a clean container with the third value pH
buffer (pH 4 or 10, or pH 4.01 or 9.18) and immerse the probe into the solution. Make sure
that the temperature sensor is immersed.
NOTE: The third buffer must not be the same as the second buffer. For example; if the
second buffer was less than pH 7, the third buffer must be greater than pH 7.
16. Press the ENTER key. The Model 63 display will now show CAL at the bottom, SLOPE
will stop flashing and the pH calibration value (automatically sensed by the instrument) is
shown with one of the decimal points flashing. If the third pH buffer is less than the first
buffer (which was used to adjust the offset; usually pH 7), the left decimal point will flash. If
the third pH buffer is greater than the first, the right decimal point will flash.
1.0.0.0pH
SLOPE
CAL 24.8°C
or
.4.0.1pH
SLOPE
CAL 24.8°C
17. When the reading is stable (does not change by 0.01 pH in 10 seconds), the decimal point
will stop flashing. Press and hold the ENTER key to save the second SLOPE. The Model 63
will flash SAVE on the display along with SLP to indicate that the second slope value has
been saved.
SAVE
SLP
The system is now calibrated at three points and will return to normal operation.
18. Rinse the probe with deionized or distilled water.
Left decimal flashes (until
reading is stable) for buffers
lower than first cal point
Right decimal flashes (until
reading is stable) for buffers
higher than first cal point
Third buffer value
Third buffer value

11
4.3 Conductivity Calibration
IMPORTANT: System calibration is rarely required because of the factory calibration of the YSI
Model 63. However, from time to time it is wise to check the system calibration and make
adjustments when necessary.
Prior to calibration of the YSI Model 63, it is important to remember the following:
1. Always use clean, properly stored, NIST traceable calibration solutions (see 12 Accessories and
Replacement Parts). When filling a calibration container prior to performing the calibration
procedures, make certain that the level of calibrant buffers is high enough in the container to
cover the entire probe. Gently agitate the probe to remove any bubbles in the conductivity cell.
2. Rinse the probe with distilled water (and wipe dry) between changes of calibration solutions.
3. During calibration, allow the probe time to stabilize with regard to temperature (approximately
60 seconds) before proceeding with the calibration process. The readings after calibration are
only as good as the calibration itself.
4. Perform conductivity calibration at a temperature as close to 25°C as possible. This will
minimize any temperature compensation error.
Follow these steps to perform an accurate calibration of the YSI Model 63:
1. Turn the instrument on and allow it to complete its self test procedure.
2. Select a calibration solution which is most similar to the sample you will be measuring.
•For sea water choose a 50 mS/cm conductivity standard (YSI Catalog# 3169)
•For fresh water choose a 1 mS/cm conductivity standard (YSI Catalog# 3167)
•For brackish water choose a 10 mS/cm conductivity standard (YSI Catalog # 3168)
3. Place at least 7 inches of solution in the plastic container (provided with the Model 63) or a
clean glass beaker.
NOTE: Do NOT use the 100 mL graduated cylinder. The diameter of the cylinder is too
small for accurate conductivity measurements.
4. Use the MODE key to advance the instrument to display conductivity.
5. Insert the probe into the solution deep enough to completely cover the probe. Both conductivity
ports must be submerged (see Figure 6 on the following page).
6. Allow at least 60 seconds for the temperature reading to become stable.
7. Move the probe vigorously from side to side to dislodge any air bubbles from the electrodes.
8. Press and release the UP ARROW and DOWN ARROW keys at the same time.
The CAL symbol will appear at the bottom left of the display to indicate that the instrument is now
in Calibration mode.

12
1000µS
CAL 24.8°C
9. Use the UP ARROW or DOWN ARROW key to adjust the reading on the display until it
matches the value of the calibration solution you are using.
10. Once the display reads the exact value of the calibration solution being used (the instrument
will make the appropriate compensation for temperature variation from 25°C), press the
ENTER key. The word “SAVE” will flash across the display for a second indicating that the
calibration has been accepted.
The YSI Model 63 is designed to retain its last conductivity calibration permanently. Therefore,
there is no need to calibrate the instrument after battery changes or power down.
4.4 Making Measurements
After the system has been set-up and pH has been calibrated as described in 4.2 pH Calibration,
it is ready to make measurements. Simply insert the probe into the sample, shake gently to
remove any trapped air bubbles and wait for the readings to stabilize (approximately 60 seconds).
The first pH reading after storage in buffers may take longer to stabilize (5 to 10 minutes),
therefore, the probe should be stored in the transport chamber when making field measurements.
It is important that the probe be inserted into the sample far enough so that the pH, temperature
and conductivity sensors are covered by the liquid (see Figure 6).
Figure 6
pH sensor (covered by sensor guard)
Upper conductivity
sensor port
Lower conductivity
sensor port

13
The Model 63 has six modes:
!pH -- Displays pH and temperature (°C).
!Conductivity -- A measurement of the conductive material in the liquid sample without regard
to temperature. Also displays temperature (°C).
!Specific Conductance -- Also known as temperature compensated conductivity which
automatically adjusts the reading to a calculated value which would have been read if the
sample had been at 25oC (or some other reference temperature which you choose). See section
5 Advanced Conductivity Setup. Also displays temperature (°C).
!Salinity-- A calculation done by the instrument electronics, based upon the conductivity and
temperature readings. Also displays temperature (°C).
!Recall -- Allows previously stored data to be displayed.
!Erase all -- Allows ALL previously stored data to be deleted.
To change between the Model 63 modes, simply press and release the MODE key. The Model
63 will cycle through the modes as follows:
pH and
Temperature °C Recall Erase all
Conductivity
and
Temperature °C
Specific
Conductance
and
Tem
p
erature °C
Salinity and
Temperature °C
NOTE: When the Model 63 is turned off, it will “remember” which mode you used last and will
return to that mode the next time it is turned on. If turned off while in recall or erase mode, it will
default to pH mode when turned on.
To determine the current mode of the Model 63, carefully observe the small legends at the far right
side of the LCD. If the instrument is reading pH, the large numbers on the display will be followed
by pH as shown below.
7.23pH
24.8°C
If the instrument is reading Conductivity, (not temperature compensated) the large numbers on
the display will be followed by either a µ
µµ
µSor an mS. Additionally, the small portion of the
display will show the oC NOT flashing.

14
3.03µS
23.8°C
If the instrument is reading Specific Conductance, the large numbers on the display will be
followed by either a µ
µµ
µSor an mS. Additionally, the small portion of the display will show the oC
flashing on and off.
If the instrument is reading Salinity, the large numbers on the display will be followed by a ppt.
32.3ppt
24.8°C
4.5 Autoranging & Range Searching
The YSI Model 63 is an autoranging instrument. This means that regardless of the conductivity
or salinity of the solution (within the specifications of the instrument) all you need to do to get
the most accurate reading is to put the probe in the sample. This feature makes the Model 63 as
simple as possible to operate.
When you first place the Model 63 probe into a sample or calibration solution, and again when
you first remove the probe the instrument will go into a range search mode that may take as long
as 5 seconds. During some range searches the instrument display will flash rANG to indicate its
movement from one range to another. The length of the range search depends on the number of
ranges which must be searched in order to find the correct range for the sample. During the range
search, the instrument will appear to freeze on a given reading for a few seconds then, once the
range is located, will pinpoint the exact reading on the display. The display may also switch to
00.0 for a second or two during a range search before it selects the proper range.
4.6 Saving Data
The Model 63 is equipped with non-volatile memory that is capable of storing up to 50 different
sets of readings. Non-volatile means that you do not need to worry that your data will be lost due
to a power failure or interruption, such as when the batteries are removed. Each set consists of
pH, conductivity, specific conductance, salinity and temperature. The Model 63 will also assign a
site identity number to each set of readings to allow easy review of the data. This feature is
useful in situations where transcribing data is difficult or not available.
Flashing °C symbol
indicates Specific
Conductance

15
SAVE
01
While pH, conductivity, specific conductance or salinity is displayed on the screen, press the
ENTER key and hold it for approximately 2 seconds. The meter will flash SAVE on the display
along with the current site identity (1 through 50) being used.
When all 50 sites are full, the display will flash FULL on the screen. This message will remain
on the screen (even after power down) until a key is pushed.
FULL
Once you have acknowledged the memory is full, any subsequent saved data will begin
overwriting existing data starting with site #1. No additional warning will be displayed.
4.7 Recalling Stored Data
1. To put the Model 63 into the RECALL mode, press the MODE key until “rcl” is displayed
on the screen along with the site ID number in the lower right corner.
rcl
01
2. Press the ENTER key to review the last set of data that was saved. The Model 63 will
display the pH and temperature. Another press of the ENTER key will display the
conductivity and the temperature.
3. Depress the ENTER key again and again to review the specific conductance and salinity
readings. All readings are displayed with the temperature.
4. Press the UP ARROW key to move up through the saved sets of data.
5. Press the DOWN ARROW key to move down through the saved sets of data.
6. When the correct Site ID# is displayed, press the ENTER key to display the data.
Site identit
y
Site identit
y

16
7. When you have finished recalling data, press MODE two times to return to normal operation.
NOTE: The Model 63 will recall data as a list. When the UP ARROW is pressed the Model 63
will display the Site ID# for the previously recorded data. For example: If you are reviewing Site
ID# 5 and the UP ARROW is pressed, the Model 63 will display Site ID#4. If you are reviewing
Site ID# 5 and Site ID# 5 was the last set of data stored, the DOWN ARROW key will display
Site ID# 1.
Here is an example of the Model 63 memory.
Site ID #1
Site ID #2
Site ID #3 If the UP ARROW key was pressed the Model 63 would display Site ID #2
Site ID #4
Site ID #5
4.8 Erasing Stored Data
1. To erase the data that is stored in the Model 63’s memory, press the MODE key until the
Model 63 displays ErAS on the screen.
2. Press and hold the DOWN ARROW and ENTER keys simultaneously for approximately 5
seconds.
ErAS
3. Successful erasure is indicated by the Model 63 displaying DONE on the display for 1 to 2
seconds.
dOnE
The instrument will automatically change to pH mode after completion and the next saved data
will be stored in site ID# 1.
IMPORTANT: Data in all 50 site ID’s will be erased completely and will be lost forever. Do
not use the erase function until all recorded data has been transcribed to an archive outside the
Model 63.