OM-25ME and OM-25MEL User Guide & Operating Instructions Rev H

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Manufacturer: Maxtec, Inc

European Representative Airox S.A. Parcd’activities Pau-Pyrenees L’echangeur BP833 64008 PAU Cedex France

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PREFACE This manual describes the function, operation and maintenance of the Maxtec Model OM-25ME and OM-25ME-L oxygen monitors. Notes are included where differences may occur between the two monitors. As members of Maxtec's MAXO2 line of oxygen analyzers and monitors, the OM-25ME utilizes the Maxtec MAX-250E oxygen sensor and is engineered for fast response, maximum reliability and stable performance. The OM-25ME is designed primarily for continuous monitoring of oxygen levels delivered by medical oxygen delivery equipment and respiratory care systems. Adjustable high and low level alarm setpoints make the OM-25ME ideal for use in neo-natal, anesthesia, and respiratory care.

THANK YOU Thank you for your purchase of a Maxtec MAXO2 oxygen monitor. We appreciate the time and energy you invest in selecting the equipment best suited to your needs. As repayment, we are supplying you with a reliable, high-quality instrument that, with proper care and operation, will provide you with years of exceptional service. We also encourage your comments or suggestions as to how our equipment, in any way, can better serve your needs. Please feel free to write, FAX or e-mail us at the address on the back of this manual c/o the Maxtec Marketing Department. NOTE: In order to obtain optimum performance from your MAXO2 monitor, all operation and maintenance must be performed in accordance with this manual. Please read the manual thoroughly before using the monitor and do not attempt any repair or procedure that is not described herein. Maxtec cannot warrant any damage resulting from misuse, unauthorized repair or improper maintenance of the instrument.

! WARNING The sensor of the MAXO2 Oxygen Monitor (MAXO2) has been tested with various anesthesia gases including Nitrous oxide, Halothane, Isoflurane, Enflurane, Sevoflurane and Desflurane and found to have acceptable low interferance, the device in its entirety (including electronics) is not suitable for use in the presense of a flammable anesthetic mixture. Only the threaded sensor face, flow diverter, and “T” adapter may be allowed to contact such a gas mixture.

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To avoid explosion, do not operate the Oxygen monitor in the presence of flammable anesthetics or in an atmosphere of explosive gases. Operating the oxygen monitor in flammable or explosive atmospheres may result in fire or explosion. Never allow an excess length of cable near the patient’s head or neck, as such could result in strangulation. Secure excess cable to the bed rail or suitable object. Never use a MAXO2 monitor with a cable that appears worn, cracked or has damaged insulation Before use, all individuals who will be using the MAXO2 must become thoroughly familiar with the information contained in this Operation Manual. Strict adherance to the operating instructions is necessary for safe effective product performance. This product will perform only as designed if installed and operated in accordance with the manufacturer’s operating instructions. Use only genuine Maxtec accessories and replacement parts. Failure to do so may seriously impair the monitor’s performance. Repair or alteration of the MAXO2 beyond the scope of the maintenance instructions or by anyone other than an authorized Maxtec service person could cause the product to fail to perform as designed. Calibrate the MAXO2 weekly when in operation and if enviromental conditions change significantly. (ie, Temperature, Humidity, Barometric Pressure. --- Refer to Calibration section of this manual). Use of the MAXO2 near devices that generate electrical fields may cause erratic readings. If the MAXO2 is ever exposed to liquids (from spills or immersion) or to any other physical abuse, turn the instrument OFF and then ON. This will allow the unit to go through its self test and make sure everything is operating correctly. Never autoclave, immerse or expose the MAXO2 (including sensor) to high temperatures (>70oC). Never expose the device to pressure, irradiation vacuum, steam, or chemicals. To protect the unit from potential leaky battery damage always remove batteries when the unit is going to be stored (not in use for 1 month) and replace dead batteries with recognized name brand AA Alkaline batteries.

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The OM-25ME-L™ oxygen monitor has been manufactured with a low alarm setting adjustable down to 15% This change is within the guidelines set forth in ASTM Specification F1462-93. The OM-25ME-L™ is labeled to indicate this feature. Classification: Protection against electric shock: Internally powered equipment. Protection against water: Ordinary equipment Mode of Operation: Continuous Sterilization: See section 6 Safety of application in the presensence of a flammable aesthetic mixture: See section 8.1 FAILURE TO COMPLY WITH THESE WARNINGS AND CAUTIONS COULD RESULT IN INSTRUMENT DAMAGE AND POSSIBLY JEOPARDIZE THE WELL BEING OF THE PATIENT AND/OR HEALTH CARE PROFESSIONAL.

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TABLE OF CONTENTS 1. SYSTEM OVERVIEW ... 1 1.1 Base Unit Description ... 1 1.2 Components Description ... 2 1.3 MAX-250E Oxygen Sensor ... 6 2. SET-UP PROCEDURE ... 7 2.1 Battery Installation ... 7 2.2 Calibrating the MAXO2 Monitor ... 7 2.2.1 Before You Begin ... 7 2.2.2 To Calibrate the MAXO2 Monitor ... 8 2.2.3 Automatic Calibration to Room Air 9 2.2.4 Factors Influencing Calibration ... 10 3. OPERATING INSTRUCTIONS ... 12 3.1 Alarm Setting Procedure ... 12 3.1.1 Low Alarm Setting ... 12 3.1.2 High Alarm Setting ... 12 3.2 Basic Operation ... 13 3.3 Alarm Conditions ... 13 4. SENSOR REMOVAL AND REPLACEMENT ... 14 5. PROBLEM SOLVING ... 15 6. CLEANING AND MAINTENANCE ... 15 7. SPECIFICATIONS ... 16 7.1 Base Unit Specifications ... 16 7.2 Sensor Specifications ... 16 8. APPLICATIONS ... 17 8.1 Exposure to Anesthetic Gases ... 17 8.2 Calibration Techniques in Pressurized Systems ... 17 8.3 Calibration Errors ... 18 8.4 Atmospheres of High Humidity ... 18 9. SPARE PARTS AND ACCESSORIES ... 20 10. WARRANTY ... 21

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1. SYSTEM OVERVIEW 1.1

Base Unit Description

The MAXO2 (Model OM-25ME) provides unparalleled performance and reliability, due to an advanced design that includes the following features and operational benefits. •

Fast-responding, oxygen-specific, galvanic sensor that achieves 90% of final value in approximately 15 seconds at room temperature.

•

Extra-life oxygen sensor of approximately 900,000 O2 percent hours (minimum 2 years in most applications).

•

External probe with 10 ft., extendible cable and diverter fitting for standard 15 mm "T" adapter.

•

Operation using 2 AA alkaline batteries (2 x 1.5 volts) for approximately 3000 hours of performance in typical usage (not in alarm conditions). For extra extended long life, 2 AA lithium batteries may be used.

•

Durable, compact case that weighs less than 1 pound and permits comfortable, hand-held operation.

•

Large, easy-to-read, 3 1/2-digit LCD display for readings in the 0-100% range.

•

Adjustable high-level and low-level alarming capability with flashing LED and audible indication of alarm conditions.

•

Simple operation and calibration using quick-calibrate key functions.

•

Self-diagnostic check of analog and microprocessor circuitry.

•

Low battery indication.

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1.2

Components Description (please refer to page 3)

A

LCD Readout

1

3 1/2-Digit Display- The 3 1/2-digit liquid crystal display (LCD) provides direct readout of oxygen concentrations in the range of 0-100%. It also displays "CAL" when the calibration mode is entered.

2

"%" Sign- In the calibration mode, the "%" sign flashes every second.

3

Low Battery Indicator- The low battery indicator appears on the LCD display when the power supply voltage drops below acceptable limits. When the "LOW BAT" icon is visible, batteries should be replaced immediately.

4

LOCKED Status Indicator- The presence of the "LOCKED" icon on the LCD readout is an indication that the unit is in its normal "LOCKED" state. The unit must be unlocked, using the LOCK key, in order to be calibrated or to change the high and low alarm settings.

5

Low Alarm Indicator- The low alarm setting is displayed at all times just below the "LOW" icon on the LCD readout. The indicated value represents the oxygen percentage at which the low alarm will be activated. In the low alarm set mode, the "LOW" icon will flash at a 1 second rate. In a low alarm condition, the low alarm value will flash in conjunction with the low alarm light emitting diode (LED).

6

High Alarm Indicator- The high alarm setting is displayed at all times just below the "HIGH" icon on the LCD readout. The indicated value represents the oxygen percentage at which the high alarm will be activated. In the high alarm set mode, the "HIGH" icon will flash at a 1 second rate. In a high alarm condition, the high alarm value will flash in conjunction with the high alarm LED.

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Threaded Mounting Bushing- Threads to Table Top Swivel Stand. Also may be used with many third party camera mounting accessories.

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1

LCD Readout

2

A

Alarm LEDs

5

3

B

6

8 9

4 15

14

13

16

10

12

11

7 C

18

Keypad

17 D External Probe

OM-25ME 3

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B

Alarm LEDs

8

Low Alarm LED- In a low alarm condition, the red "LOW ALARM" LED will flash each second, accompanied by the alarm beeper.

9

High Alarm LED- In a high alarm condition, the red "HIGH ALARM" LED will flash each second, accompanied by the alarm beeper.

C

Keypad

10

ON/OFF Key- (after Calibration) This key is used to turn the instrument on or off. When batteries are installed in the unit and the unit is in the power off mode, the display will be blank. When the ON/OFF key is pressed once, the unit will start to display the oxygen concentration and the keypad is activated. If the ON/OFF key is pressed again, the unit reverts to the power off mode.

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LOCK/UNLOCK Key- Pressing the LOCK/UNLOCK key will unlock the keypad and cause the ”LOCKED" icon to disappear from the LCD readout. The unit can then be calibrated and alarm settings can be changed if desired. If no other keys are pressed within 10 seconds, the "LOCKED" icon will reappear and the unit will revert to the "LOCKED" mode. When the unit is in the unlocked state, pressing the LOCK/UNLOCK key will also cause the "LOCKED" icon to reappear.

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CALIBRATE Key- The Unit will force you to Calibrate the first time power is applied or the sensor is changed. This is indicated on the LCD by the word “CAL”. Pressing the CALIBRATE key will allow the ↑ and ↓ arrow keys to calibrate the unit. Also when the keypad is unlocked, the CALIBRATE key is used in conjunction with the ↑ and ↓ arrow keys to calibrate the unit. When the CALIBRATE key is pressed, "CAL" appears on the LCD readout for 1 second and then the measured calibration concentration is displayed. The calibration value can then be changed using the ↑ and ↓ arrow keys. During calibration, the "%" sign will flash at a once per second rate. When the calibration value is set, pressing the CALIBRATE or LOCK/UNLOCK key will cause the unit to exit the calibration mode and return to normal operation. The unit will also revert to normal operation if 10 seconds elapse and no keys are pressed.

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↑ and ↓ Keys- The ↑ and ↓ arrow keys are used in conjunction with the CALIBRATE key to calibrate the unit or in conjunction with the LOW SET and HIGH SET keys to adjust the alarm settings. When used after pressing the CALIBRATE key, pressing the ↑ or ↓ key will raise or lower the displayed oxygen value in .1% increments. When either of these keys are held down for more than 1 second, the display will scroll at a rate of .4% per second. When used after pressing either the LOW SET or HIGH SET keys, pressing the ↑ or ↓ key will raise or lower the displayed alarm setting in 1% increments. In the alarm set mode, holding these keys down for more than 1 second will cause the display to scroll at a rate of 4% per second.

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LOW SET Key- When the keypad is unlocked, pressing the LOW SET key will cause the "LOW" icon to flash. The low alarm setting can then be changed using the ↑ and ↓ arrow keys. When the low alarm value is set and the LOW SET or LOCK/UNLOCK key is pressed again, the unit exits the alarm set mode and returns to normal operation. The unit will also revert to normal operation (storing the most recent alarm value) if 10 seconds elapse and no keys are pressed. The OM-25ME alarm setting is adjustable down to 18%. The OM-25ME-L low alarm setting is adjustable to 15%.

15

HIGH SET Key- When the keypad is unlocked, pressing the HIGH SET key will cause the "HIGH" icon to flash. The high alarm setting can then be changed using the ↑ and ↓ arrow keys. When the high alarm value is set and the HIGH SET or LOCK/UNLOCK key is pressed again, the unit exits the alarm set mode and returns to normal operation. The unit will also revert to normal operation (storing the most recent alarm value) if 10 seconds elapse and no keys are pressed.

16

SILENT Key- In an alarm condition, pressing the SILENT key will deactivate the alarm beeper, but the alarm LED and display will continue to flash. In 120 seconds, the alarm beeper will sound again. This process will be repeated until the alarm condition is cancelled. For an alarm condition to be cancelled, the concentration must be .1% higher than the alarm setting (in the presence of a low alarm condition) or .1% lower than the alarm setting (in the presence of a high alarm condition).

D External Probe Sensor with Diverter- The sensor (with diverter) is designed to fit

17 industry standard, 15 mm I.D. "T" adapters.

Extendible Cable- The extendible cable allows the sensor to be

18 positioned up to 10 feet from the side of the unit. 5

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MAX-250E Oxygen Sensor

MAX-250E oxygen sensors offer quick response, stability and extra life on the order of 900,000 percent hours. The MAX-250E is a galvanic, partial pressure sensor that is specific to oxygen. It consists of two electrodes (a cathode and an anode), a teflon membrane and an electrolyte. Oxygen diffuses through the teflon membrane and immediately reacts electrochemically at a gold cathode. Concurrently, oxidation occurs electrochemically at a lead anode, generating an electrical current and providing a voltage output. Electrodes are immersed in a unique gelled weak acid electrolyte which is responsible for the sensors long life and motion insensitive characteristic. Since the sensor is specific to oxygen, the current generated is proportional to the amount of oxygen present in the sample gas. When no oxygen is present, there is no electrochemical reaction and therefore, negligible current is produced. In this sense, the sensor is self-zeroing.

!

!

CAUTION: The Maxtec MAX-250E oxygen sensor is a sealed device containing a mild acid electrolyte, lead (Pb), and lead acetate. Lead and lead acetate are hazardous waste constituents and should be disposed of properly, or returned to Maxtec for proper disposal or recovery.

CAUTION: Do not use ethylene oxide for sterilization. Do not immerse the sensor in any cleaning solution, autoclave or expose the sensor to high temperatures.

!

CAUTION: Dropping or severely jarring the sensor after calibration may shift the calibration point enough to require recalibration.

!

CAUTION: The flow diverter for the sensor is for use with flowing gases only. Do not use the diverter when performing static sampling, such as in incubators, oxygen tents, oxygen hoods, etc.

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2. SET-UP PROCEDURE 2.1

Battery Installation

All MAXO2 units are powered by two, AA, alkaline batteries (2 x 1.5 Volts) and are shipped without the batteries installed. The battery compartment is accessible from the back side of the unit. To install the batteries: 1) With the thumb, press down on the center of the battery compartment cover and slide the cover off of the instrument case. 2) Install the two, AA, alkaline batteries (2 x 1.5 Volts) in the unit, observing the orientation shown on the label inside the compartment. 3) Slide the battery compartment cover back onto the case. Make sure the tabs on the cover snap into position, securing the cover flush against the case. When batteries are installed in the MAXO2 , the unit initiates a selfdiagnostic test. All segments of the LCD readout are turned on for approximately 2 seconds. On OM-25ME units, the alarm beeper sounds and the high and low alarm LEDs are illuminated. When the diagnostic test is completed successfully, the word "CAL" will appear on the display, indicating that the unit is ready for calibration.

2.2

Calibrating the MAXO2 Monitor

2.2.1 Before You Begin A protective film covering the threaded sensor face must be removed; wait approximately 20 minutes for the sensor to reach equilibrium. Next, the MAXO2 Oxygen Monitor should be calibrated. Thereafter, Maxtec recommends calibration on a weekly basis. However, more frequent calibration will not adversely affect product performance. More frequent calibration is recommended when: •

Calibration of the instrument should be performed when the temperature of the gas stream changes by more than 3 degrees Celsius.

•

Changes in elevation result in calibration error of approximately 1% of reading per 250 feet. In general, calibration of the instrument should

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be performed when the geographic elevation at which the product is being used changes by more than 500 feet. The sensor is best calibrated while mounted in the industry standard, 15mm I.D. “T” adapter. As in normal operation, the oxygen sensor responds best when installed in a vertical position with the sensor facing down. In addition, calibration is recommended if the user is unsure when the last calibration procedure was performed or if the measurement value displayed is in question. It is best to calibrate the MAXO2 Monitor to a known documented oxygen concentration at a pressure and flow similar to your clinical application. Calibrating the MAXO2 at lower concentrations with a known oxygen value is also acceptable and may provide additional accuracy if the calibration gas is closer to the environment in which the MAXO2 will be used. A “known” value of oxygen is defined as an oxygen source which has a traceable certificate and / or USP certification. Note: Before beginning calibration the MAX-250E sensor must be in thermal equilibrium. You may also need to be aware of other factors which affect device calibration values. For more information, refer to “Factors Influencing Calibration and Performance” in this manual.

2.2.2 To Calibrate the MAXO2 Monitor 1) Place the external probe in a stream of gas of known oxygen concentration. Expose the sensor to the calibration gas at a regulated pressure and flow. 2) Using the ON/OFF key, make sure the unit is in the power on mode. 3) Allow the oxygen reading to stabilize. This will normally take about 30 seconds or more. 4) Press the LOCK/UNLOCK key to unlock the keypad. The "LOCKED" icon will disappear from the display. 5) Press the CALIBRATE key on the keypad. The word "CAL" will appear on the display for about 1 second and then the "%" sign will start to flash.

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6) Use the ↑ and ↓ arrow keys to adjust the displayed oxygen concentration to the level of the known concentration. Pressing the arrow keys changes the value in .1% increments. If the keys are held down for more than 1 second the display will scroll at a rate of .4% per second. Note: If 10 seconds elapse between key actuations, the system will store the latest calibration value and will revert to normal operation. If this occurs inadvertently, simply repeat the calibration procedure. 7) When the calibration value is set, press the CALIBRATE or LOCKUNLOCK key again to accept the calibration setting and return to normal operation. Note: If the message "CAL," followed by the message "Er" flashes on the display after entering the desired calibration value, the system has determined that the entered value will not allow operation within the specified output range of the sensor. This situation may occur if: a) the operator has inadvertently entered the wrong concentration for the calibration gas. b) the concentration of the calibration gas is not correct. c) the sensor is in need of replacement. d) the operator attempted to adjust the monitor before allowing sufficient time for the calibration gas to purge out the previous sample. e) the flow and pressure of the calibration gas was not properly regulated. Check these items and repeat calibration. If calibration error continues to occur, contact the service department of the distributor from which the unit was purchased, or you may call Maxtec's Customer Service Department directly.

2.2.3 Automatic Calibration to Room Air The MAXO2 Monitor can quickly be calibrated to room air (20.9%) using a quick-key shortcut command. This function saves time by setting the calibration value to 20.9% without scrolling the display.

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To use this function: 1) Place the external probe in room air. 2) Press the LOCKUNLOCK key to unlock the keypad. 3) Press and hold down the CALIBRATE key. When the "%" sign starts to flash, press the ↓ arrow key to set the calibration value to 20.9%. 4) Release both the CALIBRATE key and the ↓ key. The unit will automatically enter the “LOCKED” condition and return to normal operation.

2.2.4 Factors Influencing Calibration The primary factors influencing the MAXO2 Monitor are temperature, pressure, and humidity.

Effects of Temperature The MAXO2 Monitor will hold calibration and read correctly within ±3% when in thermal equilibrium within the operating temperature range. The device must be thermally stable when calibrated and allowed to thermally stabilize after experiencing temperature changes before reading are accurate. For these reasons, the following is recommended: 1) Allow adequate time for the sensor to equilibrate to a new ambient temperature. 2) When used in a breathing circuit, place the sensor upstream of the heater. 3) For best results, perform the calibration procedure at a temperature close to the temperature where analysis will occur.

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Pressure Effect Readings from the MAXO2 Monitor are proportional to the partial pressure of oxygen. The partial pressure of Oxygen (PO2) is equal to the percentage of oxygen (%O2) times the absolute pressure (AP) at which the sample enviroment is measured. (PO2=%O2 x AP). Thus the readings are proportional to the concentration if the pressure is held constant. Flow rate of sample gas can affect pressure at the sensor in that back pressure at the sensing point may change. For these reasons, the following is recommended: 1) Calibrate the MAXO2 Monitor at the same pressure as the sample gas. 2) If sample gases flow through tubing, use the same apparatus and flow rates when calibrating as when measuring. 3) The MAXO2 Monitor oxygen sensor has been validated at pressures up to 2 atmospheres absolute. Calibration or operation above this pressure is beyond the intended use.

Humidity Effect Humidity has no effect on the performance of the MAXO2 Monitor other than diluting the gas, as long as there is no condensation. Depending on the humidity, the gas may be diluted by as much as 4%, which proportionally reduces the oxygen concentration from the dry concentration. Environments where condensation may occur are to be avoided since condensate may obstruct passage of gas to the sensing surface, resulting in erroneous readings and slower response time. For this reason, the following is recommended: 1) Avoid usage in environments greater than 95% relative humidity. 2) When used in a breathing circuit, place the sensor upstream of the humidifier.

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3. OPERATING INSTRUCTIONS 3.1 Alarm Setting Procedure 3.1.1 Low Alarm Setting To adjust the low alarm setting: 1) Press the LOCK/UNLOCK key to unlock the keypad. 2) Press the LOW SET key. The "LOW" icon will start to flash. 3) Use the ↑ and ↓ arrow keys to set the low alarm to the desired value. Pressing the arrow keys changes the value in 1% increments. If the keys are held down for more than 1 second the display will scroll at a rate of 4% per second. Note: If 10 seconds elapse between key actuations, the system will store the latest low alarm value and will revert to normal operation. If this occurs inadvertently, simply repeat the alarm setting procedure. The low alarm value cannot be set lower than 18%, nor can it be set closer than 1% from the high alarm value due to ASTM specifications (special applications requiring alarms below 18% can be accomodated by the model OM-25ME-L Monitor). For example, if the high alarm is set at 25%, the system will not accept a low alarm setting greater than 24%. 4) When the low alarm value is set, press the LOW SET or LOCK/UNLOCK key again to accept the low alarm setting and return to normal operation. Note: To automatically set the low alarm to 18% without scrolling the display, hold the LOW SET key down and press the ↓ arrow key when the "LOW" icon is flashing.

3.1.2 High Alarm Setting To adjust the high alarm setting: 1) Press the LOCK/UNLOCK key to unlock the keypad. 2) Press the HIGH SET key. The "HIGH" icon will start to flash. 3) Use the ↑ and ↓ arrow keys to set the high alarm to the desired value.

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The high alarm value cannot be set closer than 1% from the low alarm value due to ASTM specifications. For example, if the low alarm is set at 50%, the system will not accept a high alarm setting less than 51%. Setting the high alarm to 100% turns off or deactivates the high alarm. 4) When the high alarm value is set, press the HIGH SET key again to accept the high alarm setting and return to normal operation. Note: To automatically set the high alarm to 50% without scrolling the display, hold the HIGH SET key down and then press the ↓ arrow key when the "HIGH" icon is flashing. To automatically turn off the high alarm or set it to 100%, hold the HIGH SET key down and then press the ↑ arrow key when the "HIGH" icon is flashing.

3.2 Basic Operation To check the oxygen concentration of a sample gas: 1) Place the external probe in the sample gas stream. When using a standard "T" adapter, make sure the sensor is mounted in the adapter with the flow diverter pointing downward. This will prevent moisture from draining into the sensor membrane. Note: It is important that a tight fit exists between the probe and the "T" adapter. 2) Initiate flow of the sample gas to the sensor. 3) Using the ON/OFF key, make sure the unit is in the power on mode. 4) Allow the oxygen reading to stabilize. This will normally take about 30 seconds or more.

3.3 Alarm Conditions In the event of either a low alarm or high alarm condition, the corresponding LED will begin to flash, accompanied by the alarm beeper. Pressing the SILENT key will deactivate the buzzer but the LED and the alarm value digits on the display will continue to flash until the alarm condition has been rectified. If the alarm condition still exists 120 seconds after silencing the alarm beeper, the beeper will start to sound again. A low alarm condition will remain until the actual concentration is .1% higher than the low alarm setting. A high alarm condition will remain until the the actual concentration is .1% lower than the high alarm setting.

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