Thermo Fisher Scientific DO 700 User Manual

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Instruction Manual

DO 700 Dissolved Oxygen/ºC/ºF

Bench Meter

Part of Thermo Fisher Scientific 68X541703 Rev.3 . Nov 2010

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TABLE OF CONTENTS

1. INTRODUCTION.............................................................. 1

2. GETTING STARTED........................................................ 2

2.1 Keypad Functions ...................................................................2

2.2 LCD Annunciators...................................................................3

2.3 Meter Connections..................................................................3

3. DISSOLVED OXYGEN / ATC ELECTRODE................... 4

4. CALIBRATION................................................................. 5

4.1 Temperature Calibration .........................................................6

4.2 % Saturation Calibration .........................................................7

4.3 100% Calibration.....................................................................7

4.4 0% Calibration.........................................................................7

4.5 mg/L or ppm (Concentration) Calibration................................8

5. SETUP FUNCTIONS........................................................ 9

5.1 1.0 CAL (Calibration)...............................................................9

5.2 2.0 ELE (Electrode Information)..............................................10

5.3 3.0 ConF (Configuration).........................................................10

5.4 3.1 rdY (Ready Stability Indicator / Auto Hold)........................10

5.5 3.2 ºC ºF (Celsius or Fahrenheit) ............................................10

5.6 3.3 dPr (Barometric Pressure Adjustment)..............................11

5.7 3.4 SALt (Salinity Adjustment) ................................................11

5.8 3.5 OFS (Offset Adjustment) from % mode.............................11

5.9 3.5 Unit (Unit Adjustment) from concentration mode...............12

5.10 4.0 rSt (Reset).........................................................................12

5.11 5.0 CLr (Clear Stored Memory)...............................................12

6. TAKING MEASUREMENTS............................................ 13

6.1 HOLD Function .......................................................................14

6.2 Storing and Recalling Data .....................................................14

7. ELECTRODE MAINTENANCE........................................ 15

8. DISSOLVED OXYGEN THEORY .................................... 18

REPLACEMENTS AND ACCESSORIES........................ 22

10. TROUBLESHOOTING GUIDE......................................... 23

11. SPECIFICATIONS............................................................ 25

12. WARRANTY..................................................................... 26

13. RETURN OF ITEMS......................................................... 27

1. INTRODUCTION

Thank you for purchasing our DO 700 series benchtop meter. This microprocessor-based meter is economical and simple to use. The design incorporates a large LCD for clear viewing, yet offers a small footprint to conserve space.

The DO 700 measures Dissolved Oxygen in % saturation or concentration (mg/L or ppm) with temperature (ºC or ºF).

Each meter includes a convenient slide-out card for quick reference. Also included is an electrode arm and metal bracket which can be easily attached to the left or right side of the meter according to your preference.

We take great pride in every instrument we manufacture and hope this one serves you well.

2. GETTING STARTED

2.1 Keypad Functions

Powers the meter on and off. Upon power on, the meter automatically begins in the mode that was last used. Calibration and memory values are retained even if meter is unplugged.

Toggle between available measurement modes—% saturation or concentration (mg/L or ppm). Also used to switch to Temperature calibration during DO calibration modes.

Press and hold for 5 seconds to enter SETUP mode.

Toggles between measurement and calibration modes. In SETUP mode, returns user to the measurement mode.

Confirms calibration values in CAL mode. Confirms selections in SETUP mode. View recalled values in memory mode.

S Increase value. Scroll up in SETUP & CAL modes.

MI (Memory Insert) stores values into memory.

MR (Memory Recall) recalls values from memory.

T Decrease value. Scroll down in SETUP & CAL modes.

Freezes measured reading. Press again to resume live reading.

2.2 LCD Annunciators

2.3 Meter Connections

ATC

Power supply Temperature connection of Dissolved Oxygen electrode BNC connection of Dissolved Oxygen electrode

3. DISSOLVED OXYGEN / ATC ELECTRODE

The DO 700 includes a galvanic DO electrode with built in temperature measurement.

The electrode has a dual cable; a BNC connector for DO measurement and a miniphono plug for temperature. The electrode is pre-filled with electrolyte that is separated from the sample by an oxygen permeable membrane. The membrane is pre-assembled for you and fixed to a detachable cap. The pre-assembled cap design allows simple replacement and fast conditioning.

The electrode is light-weight with a 12-mm body diameter and a 16-mm tip diameter from at the detachable Noryl cap. The compact sensing area reduces air entrapment resulting in quick, accurate, and stable readings.

Provide simple stirring for best results— ideally achieve a minimum water flow rate of 2 inch/second on the membrane.

The probe is not recommended for samples beyond 0 to 50 °C.

The membrane is thin and can be replaced if damaged. Use care to protect from scratches, abrasion, or contact with solids. For best results keep membrane clean by rinsing after daily use. See Section 7

– Electrode Maintenance.

4. CALIBRATION

The DO 700 has three measurement modes; DO as % saturation, DO as mg/L (or ppm) concentration, and temperature.

Dissolved oxygen levels vary with temperature, barometric pressure, and salinity, so calibration must be performed with consideration of these factors. It is necessary to set the proper temperature,

barometric pressure and salinity values prior to performing any DO calibration or measurement.

See

Section 4.1 — Temperature Calibration

See Section 5.6 — Barometric Pressure Adjustment. See Section 5.7 — Salinity Adjustment.

The DO 700 will accept two % saturation calibration points; 100% using saturated air or air-saturated water, and 0% using zero oxygen solution. When 100% or 0% calibration is performed, the concentration value is adjusted accordingly. Therefore, it is not necessary to calibrate the concentration mode. If calibrating for 0% oxygen, note that the meter will take several minutes to reach 0% saturation value and constant stirring is not required.

The following table lists calibration values in % saturation calibration mode with two different barometric pressures. Note that the saturation value (92.1%) has decreased due to the lower barometric pressure entered.

% Saturation

(of factory default value)

less than 10% 0% 0%

10.1% to 49.9% CAL ERR CAL ERR 50% to 150% 100% 92.1%

Calibration Value

(760mmHg)

Calibration Value

(700mmHg)

If calibration is attempted from 10.1% to 49.9%, CAL Err message is shown—calibration is rejected and the display will return to calibration mode.

The DO 700 will accept one calibration point in concentration mode. The minimum value is 2 mg/L (ppm), and the calibration window is +/40% of the factory default value.

Temperature and % saturation calibration should take place before attempting to perform mg/L (ppm) concentration calibration.

Calibration of the concentration mode will only replace the previous concentration calibration and does not affect the % saturation calibration.

To offset your % saturation reading to match another instrument, see

Section 5.8 – Offset Adjustment

Perform daily calibration for best results. New calibration values will automatically override the existing data. To completely recalibrate the meter and when installing a replacement electrode, it is best to clear all calibration data. See Section 5.10 – Reset.

4.1 Temperature Calibration

For best DO accuracy, ensure that the temperature is accurate. The thermistor sensor used for automatic temperature compensation and measurement is accurate and stable, so frequent calibration isn’t required. Temperature calibration is recommended upon probe replacement, whenever the temperature reading is suspect, or if matching against a certified thermometer is desired.

The DO 700 will default to 25 ºC / 77 ºF when the ATC plug is not connected.

1) Place the pr obe into a solution with a known accurate temperature such as a constant temperature bath.

2) Press measured temperature while the secondary displa y shows the factory default temperature.

4) Adjust the temperature using or . Press to accept or

C (or ± 9ºF) from the factory default temperature.

followed by . The primary display shows the

to cancel. The meter allows an adjustable maximum value of ±

4.2 % Saturation Calibration

The DO700 can be easily calibrated in air. For best accuracy, ensure that the barometric pressure value is accurate.

The barometric pressure factory default is 760 mm Hg (1.013 bar), which results in a theoretical calibration value of 100% saturation in air. If the barometric pressure setting has been changed from 760 mm Hg, the meter will automatically adjust to a new % saturation calibration value instead of 100%. This new value is correct for the adjusted barometric pressure.

4.3 100% Calibration

1) Rinse the probe well with clean water (do not dry).

2) Press

3) Hold the probe in the air with the tip facing downwards. Wait for

the reading to stabilize.

4) Press

indicate the calibration point, 100.0.

5) Press

briefly before calibrating to 100.0%.

6) Press

calibration if desired.

4.4 0% Calibration

1) Rinse the probe well with clean water (do not dry).

2) Press

3) Submerse probe in zero oxygen calibration solution and stir

slowly. Wait for the reading to stabilize—this can often take more than 10 minutes!

to select % saturation.

. The CAL indicator will blink and secondary display will

to confirm the calibration. The pr imary display wil l blink

to return to measurement mode, or continue with 0%

to select % saturation.

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