Oakton pH 700, Ion 700 Instruction Manual

Notes

Write down the name and information of your OAKTON distributor here.

OPERATING INSTRUCTIONS

OAKTON® 35632-Series

Portable Waterproof

pH/Dissolved Oxygen

Meter

WATERPROOF

MEAS

%

READY

C

ATC

pH/Dissolved Oxygen/°C/°F Meter

pH/DO 300 Series

	ON	HOLD	MODE
	OFF
		CAL	ENTER
		MEAS
		▲	▼
	IP
	67
			SETUP

Table of Contents

1.	Introduction............................................................................................		4
2.	Display and keypad functions .............................................................		5-6
	2.1 Display ...................................................................................................................................		5
	2.2 Keypad ...................................................................................................................................		6
3.	Preparation..........................................................................................		7-9
	3.1 Inserting the batteries ..........................................................................................................		7
	3.2 Probe information — Connecting the probes...............................................................		8-9
4.	Calibration .......................................................................................		10-19
	4.1	Important information on meter calibration .................................................................	10
	4.2	Preparing the meter for pH calibration ..........................................................................	11
	4.3 pH calibration................................................................................................................		12-13
	4.4	Preparing the meter for DO calibration..........................................................................	14
	4.5	Dissolved oxygen calibration in % saturation..........................................................	15-16
	4.6	Dissolved oxygen calibration in mg/l (ppm) mode ...............................................	17-18
	4.7	Temperature calibration ....................................................................................................	19
5.	Measurement ...................................................................................		20-24
	5.1	Taking DO readings......................................................................................................	20-21
	5.2	Taking pressure/salinity compensated DO measurements...................................	21-22
	5.3	Taking pH readings ......................................................................................................	23-24
	5.4	Manual temperature compensation ................................................................................	25
6.	Hold function........................................................................................		26
7.	Backlit LCD............................................................................................		27
8.	Advanced SETUP functions ..............................................................		28-55
	8.1 Advanced setup mode overview................................................................................		29-31
		pH measurement mode overview ................................................................................	29
		% saturation measurement mode overview ...............................................................	30
		mg/l (ppm) measurement mode overview.................................................................	31
	8.2 pH mode—Program P1.0: Viewing previous calibration data....................................		32
	8.3 pH mode—Program P2.0: Viewing electrode data..................................................		33-34
		P2.1 Electrode offset .........................................................................................................	33
		P2.2 Electrode slope .........................................................................................................	34
	8.4 pH mode—Program P3.0: pH measurement configuration...................................		35-37
		P3.1 READY indicator and auto endpoint function....................................................	35
		P3.2 Selecting number of pH calibration points..........................................................	36
		P3.3 Selecting °C or °F .....................................................................................................	37

8.5 pH mode—Program P4.0: Resetting to factory default settings.................................		38
8.6 % saturation mode—Program P1.0: Dissolved oxygen parameters
	Pressure adjustment mode..............................................................................................	39
8.7 % saturation mode—Program P2.0: Offset adjustment................................................		40
8.8 % saturation mode—Program P3.0: Previous calibration information......................		41
8.9 % saturation mode—Program P4.0: Electrode properties ...........................................		42
8.10 % saturation mode—Program P5.0: Unit configuration.......................................		43-44
	P5.1 READY indicator and auto endpoint function....................................................	43
	P5.2 Selecting °C or °F temperature readout................................................................	44
8.11 % saturation mode—Program P6.0: Adjusting LCD brightness ...............................		45
8.12 % saturation mode—Program P7.0: Resetting to factory default .............................		46
8.13 mg/l (ppm) mode—Program P1.0: Dissolved oxygen parameters ....................		47-48
	P1.1 Pressure adjustment mode .....................................................................................	47
	P1.2 Salinity adjustment mode.......................................................................................	48
8.14 mg/l (ppm) mode—Program P2.0: Previous calibration information.....................		49
8.15 mg/l (ppm) mode—Program P3.0: Electrode properties ..........................................		50
8.16 mg/l (ppm) mode—Program P4.0: Unit configuration........................................		51-53
	P4.1 READY indicator and auto endpoint function....................................................	51
	P4.2 Selecting mg/l or ppm units..................................................................................	52
	P4.3 Selecting °C or °F temperature readout................................................................	53
8.17 mg/l (ppm) mode—Program P5.0: Adjusting LCD brightness................................		54
8.18 mg/l (ppm) mode—Program P6.0: Resetting to factory default ..............................		55
9. Probe care and maintenance...........................................................		56-60
9.1 pH electrode care ..........................................................................................................		56-57
9.2 DO probe care .....................................................................................................................		57
9.3 Membrane replacement ...............................................................................................		58-59
9.4 Electrolyte solution ............................................................................................................		60
10.	Troubleshooting..................................................................................	61
11.	Error Messages....................................................................................	62
12.	Specifications ......................................................................................	63
13.	Accessories .....................................................................................	64-65
14.	Appendix 1: Meter theory ..................................................................	66
15.	Appendix 2: Pressure vs. Altitude table.............................................	67
16.	Appendix 3: Factory default settings.................................................	68
17.	Warranty .............................................................................................	69
18.	Return of Items...................................................................................	69

2

3

1. Introduction

Thank you for selecting an OAKTON meter. This OAKTON portable meter

is a microprocessor-based instrument that measures pH, dissolved oxygen and temperature. It’s completely waterproof—and it floats! Your meter has many user-friendly features, all of which are accessible through the membrane keypad.

Your meter includes batteries. Please read this manual thoroughly before operating your meter.

	WATERPROOF
MEAS		%
READY
		C
		ATC
pH/Dissolved Oxygen/°C/°F Meter
pH/DO 300 Series
ON	HOLD	MODE
OFF
	CAL	ENTER
	MEAS
	▲	▼
		SETUP

2.Display and Keypad Functions

2.1Display

The LCD has a primary and secondary display.

•The primary display shows the measured pH or dissolved oxygen reading.

•The secondary display shows the temperature of the reading.

The display also shows error messages, keypad functions and program functions.

Primary display

1.		2.		3.		4.	5.

SETUP

MEAS

CAL

pH%

READY

16.

6.

15.

HOLD

ppt

ON

ppm

7.

14.

mg/l

OFF

C F

ERR

8.

13.

ATC

9.

12.

11. 10.

Secondary display

1. SETUP mode indicator

8. Temperature

14. Function ON/OFF

2. MEASurement mode

indicators

indicator

9. Automatic Temperature

15. HOLD indicator

indicator

3. CALibration mode

Compensation

16. READY indicator

indicator

indicator

10. ERRor indicator

4. pH indicator

11. Low battery indicator

5. % saturation indicator

12. Probe indicator

6. Salinity input indicator

7. Oxygen solubility

13. Calibration data

indicators

indicator

4

5

2.2 Keypad

The large membrane keypad makes the instrument easy to use. Each button, when pressed, has a corresponding graphic indicator on the LCD.

ON/OFF............	Powers and shuts off the meter.
HOLD ..............	Freezes the measured reading. To activate, press HOLD while in
	measurement mode. To release, press HOLD again.
	NOTE: When auto endpoint feature is switched on, it automatically
	holds reading after 5 seconds of stability. The HOLD indicator
	appears on the display. Press HOLD to release.
MODE ..............	Selects the measurement parameter. Press MODE to toggle between
	pH; DO % saturation; DO mg/l (ppm). In pH and DO mg/l (ppm)
	calibration modes press MODE to access temperature calibration.
	NOTE: To switch between mg/l and ppm modes, see page 52.
CAL/MEAS......	Toggles user between Calibration and Measurement mode.
	• If you were in pH mode, press CAL/MEAS to enter
	pH calibration mode.
	• If you were in DO % saturation mode, press CAL/MEAS to enter
	DO % saturation calibration mode.
	• If you were in DO mg/l (ppm) mode, press CAL/MEAS
	to enter DO mg/l (ppm) calibration mode.
	NOTE: Temperature calibration is available from both pH and DO
	mg/l (ppm) calibration modes; see page 19 for directions.
	In advanced set-up mode: Press CAL/MEAS to return to main menu
	from sub menus. Press CAL/MEAS again to return to measurement
	mode from main menu.

ENTER ............Press to confirm values in Calibration mode and to confirm selections in SETUP mode.

▲ ▼	..........Press in SETUP mode to
	scroll through subgroups.
	Also lets you increment/
	decrement the values in
	the mg/l and temperature
	calibration modes.
SETUP ..............	Press to enter SETUP
	mode. SETUP mode lets
	you customize meter
	preferences and defaults,
	and view calibration and
	probe data.
..........................	LIGHT Press to activate
	backlit display.

	ON	HOLD	MODE
	OFF
		CAL	ENTER
		MEAS

▲▼

SETUP

3. Preparation

3.1 Inserting the Batteries

Four AAA batteries are included with your meter.

1.Use a Phillips screwdriver to remove the two screws holding the battery cover. See figure below.

2.Lift off battery cover to expose batteries.

3.Insert batteries. Follow the diagram inside the cover for correct polarity.

4.Replace the battery cover into its original position. Screw cover back into place.

Remove these two screws to access battery compartment

Battery compartment

6

7

3.2 Probe information

Your meter uses two probes:

•pH electrode with BNC connector

•dissolved oxygen/temperature probe with a notched 6-pin connector

The temperature sensing element built into the dissolved oxygen probe will also compensate for pH readings as long as both probes are in your solution at the same time.

You can use any standard pH electrode with a BNC connector with this meter. If you do not have the DO probe connected you will need temperature probe 35618-05 to provide temperature compensation for pH readings (not included

order separately). For the dissolved oxygen/temperature probe, you must use an OAKTON dissolved oxygen/temperature probe with the notched 6-pin connector. For replacement probes, see the “Accessories” section, pages 64-65.

NOTE: Keep connectors dry and clean. Do not touch connectors with soiled hands.

To connect the pH electrode:

1.Slide the BNC connector of the probe over the BNC connector socket on the meter. Make sure the slots of the connector are in line with the posts of the socket. Rotate and push the connector clockwise until it locks.

See figure below.

2.To remove probe, push and rotate the connector counterclockwise. While holding onto the metal part of the connector, pull probe away from the meter.

CAUTION: Do not pull on the probe cord or the probe wires might disconnect.

To connect the dissolved oxygen probe:

NOTE: Do not substitute other DO probes. For a replacement DO probe, see the “Accessories” section, page 64.

1.Line up the notch and 6 pins on the meter with the holes in the 6-pin connector. Push down and turn the locking ring clockwise to lock into place.

See figure below.

2.To remove probe, turn the locking ring counterclockwise on the probe connector. Pull probe away from the meter.

CAUTION: Do not pull on the probe cord or the probe wires might disconnect.

pH Electrode	DO probe
(with BNC connector)	(with 6-pin connector)
	locking ring
	top view of 6-pin
	connector of
	DO probe

8

9

4. Calibration

4.1 Important Information on Meter Calibration

When you recalibrate your meter, old calibration points are replaced on a “point by point” basis in pH and completely for % saturation and mg/l (ppm).

For example:

•pH: if you previously calibrated your meter at pH 4.01, 7.00, and 10.01, and you recalibrate at pH 7.00, the meter retains the old calibration data at pH 4.01 and pH 10.01.

•% saturation and mg/l (ppm): All new calibrations automatically override existing calibration data.

To view current calibration points:

•pH: Program P1.0 in the SETUP section, page 32.

•% saturation: Program P3.0 in the SETUP section, page 41.

•mg/l (ppm): Program P2.0 in the SETUP section, page 49.

To completely recalibrate your meter, or when you use replacement probes, it is best to clear old calibration data by resetting the meter.

To reset the meter to its factory defaults:

•pH: Program P4.0 in the SETUP section, page 38.

•% saturation: Program P7.0 in the SETUP section, page 46.

•mg/l (ppm): Program P6.0 in the SETUP section, page 55.

NOTE: Resetting the meter will set meter to factory defaults.

pH, % saturation and mg/l (ppm) must be reset separately.

For directions on how to calibrate your meter:

•See sections 4.2-4.3 on pages 11-13 for pH calibration

•See section 4.4-4.5 on page 14-16 for % saturation calibration

•See section 4.4 and 4.6 on page 14, 17-18 for mg/l (ppm) calibration

•See section 4.7 on pages 19 for Temperature Calibration

4.2 Preparing the Meter for pH Calibration

Before starting pH calibration, make sure you are in the correct measurement mode. When you switch on the meter, the meter starts up in the units last used. For example, if you shut the meter off in "pH" units, the meter will read "pH" units when you switch the meter on.

Do not reuse pH calibration solutions after calibration. Contaminants in the solution can affect the calibration, and eventually the accuracy of the measurements. See pages 64-65 for information on our high-quality pH calibration solutions.

Be sure to remove the protective rubber cap from the pH electrode before calibration or measurement. If the electrode has been stored dry, wet the probe in tap water for 10 minutes before calibrating or taking readings to saturate the pH electrode surface and minimize drift.

Wash your probe in deionized water after use, and store in electrode storage solution. If storage solution is not available, use pH 4.0 or 7.0 buffer.

The pH/DO 300 meter is capable of up to 5-point pH calibration at pH 1.68, 4.01, 7.00, 10.01, and 12.45 to ensure accuracy across the entire pH range of the meter . The meter automatically recognizes and calibrates to these standard buffer values, which makes pH calibration faster and easier.

To calibrate at 5 points you must select a 5-pt calibration in SETUP mode program P3.2 on page 36. You can select 2, 3, 4 or 5 calibration points for pH calibration.

10

11

4.3 pH calibration

NOTE: We recommend that you perform at least a 2-point calibration using standard buffers that bracket (one above and one below) the expected sample range. You can perform a 1-point calibration, but make sure that the buffer value is close to the sample value you are measuring.

The temperature sensing element is in the DO probe. For temperature compensated readings and calibration, immerse the DO probe into the calibration buffer while calibrating pH.

pH Calibration

1.If necessary, press the MODE key to select pH mode. The pH indicator appears in the upper right hand corner of the display.

See figure A

2.Rinse the pH electrode and DO probe thoroughly with de-ionized water or a rinse solution. Do not wipe the probe; this causes a build-up of electrostatic charge on the glass surface.

3.Dip both probes into the calibration buffer. The end of both probes must be completely immersed into the sample. Stir the probe gently to create a homogeneous sample.

4.Press CAL/MEAS to enter pH calibration mode. The CAL indicator lights. The primary display will show the measured reading while the smaller secondary display will indicate the pH standard buffer solution.

See figure	B
5. Wait	the measured pH value to

stabilize

See figure

MEAS

pH

C

ATC

CAL

pH

pH

B

CAL

READY

pH

pH

C

If the READY indicator has been activated

(set up program P3.1—see page 35), the READY annunciator lights when the reading is stable.

6. Press ENTER to confirm calibration.

The meter is now calibrated to the
current buffer.										CAL
See figure D			READY							pH
• If you are performing multipoint
calibration, go to step 7.										pH
• If you are
	D
calibration,

7.Rinse the probe with de-ionized water or a rinse solution, and place it in the next pH buffer.

8.Follow steps 5 to 8 for additional calibration points.

9.When calibration is complete, press CAL/MEAS to return to pH measurement mode.

Notes

To exit from pH Calibration mode without confirming calibration, DO NOT press

ENTER in step 6. Press CAL/MEAS instead.

If the selected buffer value is not within ±1.0 pH from the measured pH value: the electrode and buffer icon blink and the ERR annunciator appears in the lower left corner of the display.

To limit the number of pH buffer values available during calibration, see section P3.2 on page 36.

12

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4.4 Preparing the meter for DO calibration

Before calibrating your meter, make sure to rinse the DO probe well with de-ionized water or rinse solution.

NOTE: Do not let membrane surface of the DO probe touch any other surface. The DO probe guard (the piece with holes fitted over the end of the probe) protects the membrane; make sure this is always attached to the probe while it is in use.

You can calibrate for dissolved oxygen in either % saturation or mg/l (ppm). All new DO calibrations automatically override existing DO calibration data.

Before Dissolved Oxygen calibration

Before starting DO calibration, make sure you are in the correct measurement mode. When you switch on the meter, the meter starts up in the units last used (either pH, mg/l, ppm, % saturation). For example, if you shut the meter off in “mg/l” units, the meter will read “mg/l” units when you switch the meter on.

NOTE: Most users will calibrate to 100% saturation even when working in mg/l. When calibrating the meter in mg/l mode, you can make fine adjustments, typically to a midrange value between 10 and 100%. If you are calibrating to a midrange value, you need to set the 100% saturation value first.

4.5 Dissolved Oxygen calibration in percent saturation

You can calibrate this meter quickly and easily in air. The exact calibration value depends on barometric pressure. The meter is to a factory default of 760 mm Hg, which results in a calibration value of 100% saturation in air.

NOTE: If the barometric pressure setting has	changed from 760 mm Hg, the
calibration value in air will	adjust to a value other than 100%.
The adjusted value will be correct for	new barometric pressure setting.
• See page 39 to change the pressure setting.
• See Appendix 2 on page 67 for a	of adjusted % saturation values.

To calibrate 100 % saturation:

1. Rinse the probe well with deionized DO Probe guard rinse water or rinse solution. For best

accuracy, wrap the end of the probe in a damp cloth. Do not touch the membrane.

2.

See figure

3. Press CAL key. The CAL indicator will appear above the primary display. The primary display shows the current

value	measurement and the
secondary display will show 100.0
(see NOTE above).
See figure
4. Hold	probe in the air (or in damp
cloth).	for the reading to stabilize.
If the Ready indicator feature is enabled,
it will appear when the reading is stable
(see	43 for Ready indicator setup).
5. Press	ENTER key. The meter auto-
matically calibrates to 100.0% air satura-
tion	returns to Measurement mode.
See figure	C

MEAS

%

READY

C

ATC

A

CAL

%

READY

B

MEAS

%

READY

C

ATC

C

Notes

The reading in the primary display in step 3 must read at 50% or above for the calibration to work correctly. Whenever an error occurs during calibration, the ERR indicator appears in the lower left hand corner of the display.

You can offset your % DO calibration: see page 40 for directions.

14

15

To calibrate 0 % saturation:

1.Rinse the probe well with deionized rinse water or rinse solution. Do not touch the membrane.

2.Press the MODE key to select the % saturation mode.

See figure D
2. Place	in zero oxygen
solution	the probe gently to

homogenize the sample. Make sure that the sample is continuously flowing past the membrane sensor.

3.Press the CAL key. The CAL indicator will appear above the primary display. The primary display shows the current value of the measurement and the secondary display will show 0.0.

See figure E

4.Wait for the reading to stabilize. If the Ready indicator feature is enabled, it will appear when the reading is stable (see page 43 for Ready indicator setup).

5.Press the ENTER key. The meter automatically calibrates to 0.0% saturation and returns to Measurement mode.

See figure F

Notes

The reading in the primary display in step 3 must read at 10% or under for the calibration to work correctly. Whenever an error occurs during calibration, the ERR indicator appears in the lower left hand corner of the display.

You can offset your % DO calibration: see page 40 for directions.

MEAS

%

READY

C

ATC

CAL

%

READY

MEAS

%

READY

C

ATC

4.6 Dissolved Oxygen calibration in mg/l (ppm) mode

Calibrating the meter to 100 % in saturation mode will also calibrate the mg/l mode at the value in mg/l corresponding to 100% saturation. This should produce acceptable results in most applications.

This meter also lets you make a calibration adjustment in mg/l (ppm) mode without affecting your % saturation calibration.

To select between mg/l and ppm units, see page 52.

To calibrate in mg/l (ppm) mode:

1.Calibrate 100% saturation per section 4.5 on page 15.

2.Rinse the probe well with deionized rinse water or rinse solution. Wipe the outside of the probe carefully (do not touch the membrane).

3.Dip the probe into a sample of known oxygen concentration. Wait for the reading to stabilize. If the Ready indicator feature is enabled, it will appear when the reading is stable (see page 43 for Ready indicator setup).

NOTE: The sample must continuously flow past the membrane for accurate readings. A stirrer can keep the solution agitated; order a magnetic stirrer on page 65.

4. Press

key to select the

mg/l (ppm) mode.

See figure A

5.Press the CAL key. The CAL indicator will appear above the primary display. The

value of

ondary display shows the temperature.

See figure		B
6.	Press	and ▼ keys to adjust
	the reading.
7.	Press	ENTER key. The meter
	automatically calibrates to the
	value	entered and returns
	to Measurement mode.

See figure

MEAS

READY

mg/l

C

ATC

A

CAL

READY

mg/l

C

ATC

B

CAL

READY

mg/l

C

ATC

C

16

17

Notes on mg/l (ppm) mode calibration

During mg/l (ppm) calibration, the meter adjusts to the barometric pressure value that is programmed into the meter. It also adjusts to the salinity value that is programmed into the meter.

You can change the barometric pressure value and salinity value in the mg/l (ppm) SETUP mode (see pages 47-48 for directions).

Whenever an error occurs during calibration, the ERR indicator appears in the lower left hand corner of the display.

4.7 Temperature Calibration

The built	temperature sensor included in the DO probe is factory calibrated.
Calibrate your sensor only if you suspect sensor drift that may have occurred
over a	period of time or if you have a replacement DO probe. Make sure DO

probe is attached before you perform the temperature calibration.

1.	Switch	meter on. Press MODE to
	select either pH or mg/l (ppm)
	Measurement mode.
2.	Press	CAL/MEAS key to enter
	pH or mg/l (ppm) calibration mode.
	The	indicator will appear above the
		display.
See
3.	While	pH or mg/l (ppm) calibration
	mode,	the MODE key to enter

temperature calibration mode.

The primary display shows the last set temperature reading and the secondary display you the factory default temperature value.

See figure

4.Compare the primary display reading to a traceable thermometer or another thermometer known to be accurate

5. Press	or ▼ keys to adjust
the primary display reading to agree
with	temperature standard.

See figure C

6.Press the ENTER key to confirm temperature calibration and return to Measurement mode.

CAL

READY

mg/l

C

ATC

A

CAL

READY

C

ATC

B

CAL

READY

C

ATC

C

Notes

To exit from Temperature Calibration mode without confirming calibration, DO NOT press ENTER in step 6. Press CAL/MEAS instead.

Temperature calibration is restricted to ±5°C from the factory default value displayed during calibration (shown in the secondary display).

18

19

B

SETUP

A

SETUP

3. Use

key until the upper a number and the lower “Hg” or “PA”.

2. Press display display

1. Press the MODE key to select % saturation or mg/l (ppm) mode. Press the SETUP key to enter Set Up mode.

See figure

Taking measurements with READY indicator selected on

If the READY indicator has been activated, the READY annunciator lights when the reading is stable. Switch the READY indicator on or off in the SETUP program P5.1 for % saturation measurements (page 43) or program P4.1 (page 51) for mg/l (ppm) measurements.

Taking measurements with the auto endpoint feature selected on

When a reading is stable for more than 5 seconds, the auto endpoint feature will automatically “hold” the reading. The “hold” indicator appears on the left side of the display. Press the HOLD key to release the reading. Switch the Auto endpoint feature on or off in the SETUP program P5.1 for % saturation measurements (page 43) or program P4.1 (page 51) for mg/l (ppm) measurements.

5.2 Taking pressure/salinity compensated DO measurements

If necessary, you can adjust the pressure and salinity values of your measurements in the SETUP mode. The DO meter will automatically compensate for salinity and pressure based on the values entered in the setup functions. The meter is factory set at 760 mm Hg (101.3 Pascals) pressure adjustment and a factor of 0.0 salinity adjustment. See Appendix 2 on page 67 for a “Pressure vs Altitude” table.

Pressure adjustment

NOTE: This adjustment appears in both the % saturation and mg/l (ppm) measurement modes.

5. Measurement

5.1	Taking DO readings
During measurement, the probe can be:
• fully immersed in the solution
• partially immersed in the solution
Do not allow the probe’s membrane surface to
anything! The probe guard (the piece with		fitted
over the end of the probe) protects the membrane; you			Probe guard
should leave this piece attached to the probe		times.

IMPORTANT: since the DO probe consumes oxygen from the sample, the sample must constantly flow past the membrane to achieve more accurate readings. You can use a stirrer to accomplish this (see on page 65 for a magnetic stirrer).

To take measurements:

1.Rinse the probe well with deionized rinse water or rinse solution.

2.Select the appropriate measurement

mode. Press the MODE key to toggle				MEAS
between modes:				READY
• % saturation.				mg/l
• mg/l (ppm)**,				C
• pH				ATC
3.			A
probe gently to homogenize the sample.
Make sure that the sample is continu-
ously flowing past the membrane sensor.
4. Note		on the display. If the
READY		is switched on, it will
appear	the reading is stable.
See figure	A

**To select between mg/l and ppm units, see page 52.

The ATC indicator should appear in the lower right hand corner of the display. If it does not, this indicates an error.

CONTINUED ON NEXT PAGE

20

and ▼ keys to enter the barometric pressure. The upper display will the value you have entered.

See figure B

4. Press ENTER to confirm pressure value.

5.Press CAL/MEAS to return to measurement mode, or continue with step 4 on page 22 to make a salinity adjustment [available from mg/l (ppm) mode only].

21