Teledyne LXT-280 Operating Instructions Manual
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Teledyne LXT-280 Operating Instructions Manual

Teledyne LXT-280 Operating Instructions Manual

Dissolved oxygen transmitter
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OPERATING INSTRUCTIONS FOR
LXT-280
Dissolved Oxygen
Transmitter
P/N M
ECO:
DANGER
Toxic gases and or flammable liquids may be present in this monitoring system.
Personal protective equipment may be required when servicing this instrument.
Hazardous voltages exist on certain components internally which may persist
for a time even after the power is turned off and disconnected.
Only authorized personnel should conduct maintenance and/or servicing.
Before conducting any maintenance or servicing, consult with authorized
supervisor/manager.
Teledyne Analytical Instruments

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  • Page 1 Hazardous voltages exist on certain components internally which may persist for a time even after the power is turned off and disconnected. Only authorized personnel should conduct maintenance and/or servicing. Before conducting any maintenance or servicing, consult with authorized supervisor/manager. Teledyne Analytical Instruments...
  • Page 2 Teledyne Instruments/ Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91749- 1580.
  • Page 3 Dissolved Oxygen Transmitter Specific Model Information Instrument Serial Number: _______________________ Instrument Range: _______________ Calibrated for: _______________ Teledyne Analytical Instruments...

  • Page 4: Safety Messages

    NOTE: Additional information and comments regarding a specific component or procedure are highlighted in the form Symbol of a note. CAUTION: THE ANALYZER SHOULD ONLY BE USED FOR THE PURPOSE AND IN THE MANNER DESCRIBED IN THIS MANUAL. Teledyne Analytical Instruments...
  • Page 5 Manuals do get lost. Additional manuals can be obtained from TI/AI at the address given in the Appendix. Some of our manuals are available in electronic form via the internet. Please visit our website at: www.teledyne-ai.com. Teledyne Analytical Instruments...

  • Page 6: Table Of Contents

    2.1 Unpacking the Instrument 2.2 Mounting 2.3 Wiring 2.3.1 Site Wiring 2.3.2 Power Wiring 2.3.3 Sensor Wiring 2.3.4 DC Power 2.4 Configuring the LXT-280 2.5 Calibration Operation ..................11 3.1 Using the Front Panel Keys 3.2 Menus 3.2.1 Contrast 3.2.2 Main Menu 3.2.3 Electrode Data Screen...
  • Page 7 5.2 Salinity Correction 5.3 Calibration Example 5.4 Grab Sample Calibration 5.5 Dissolved Oxygen Units of Measurement Maintenance ................37 6.1 Routine Maintenance 6.1.1 Cleaning 6.1.2 Replacement of the Microprocessor: Appendix ..................41 A.1 Specifications A.2 Spare Parts Listing Index ....................45 Teledyne Analytical Instruments...

  • Page 8: List Of Figures

    LXT-280 List of Figures Figure 1-1: LXT-280 User Interface ..........3 Figure 2-1: Typical Installation for the LXT-280 Transmitter.... 6 Figure 2-2: Intrinsically Safe Wiring Diagram ........7 Figure 2-3: LXT-280 Wiring ............8 Figure 3-1: LXT-280 Operator Interface........11 Figure 3-2: Available Menus ............
  • Page 9 Dissolved Oxygen Transmitter List of Tables Table 5-1: Oxygen Saturation vs. Temperature......32 Table 5-2: Relative Humidity Correction Factors ......33 Table 5-3: Elevation Correction Factor ..........33 Table 5-4: Salinity Correction Factor ..........34 Table 6-1: Troubleshooting ............38 Teledyne Analytical Instruments...
  • Page 10 Since the use of this instrument is beyond the control of Teledyne, no responsibility by Teledyne, its affiliates, and agents for damage or injury from misuse or neglect of this equipment is implied or assumed.

  • Page 11: Introduction

    Class I, II, and III Divisions 1 Groups A through G hazardous areas. The Model LXT-280 transmitters provide solutions to a variety of liquid analytic applications involving hazardous areas. The LXT-280 accepts input from a variety of sensors for specific process measurements such as: • Dissolved Oxygen (DO) •...

  • Page 12: Main Features Of The Transmitter

    1.3 Optional Features The Model LXT-280 Transmitter is a versatile instrument designed to meet the needs for liquid analytics and process control across a wide range of applications. Options available for this transmitter includes: Optional Software Security Access—keyboard security option: Allows only...

  • Page 13: Figure 1-1: Lxt-280 User Interface

    Dissolved Oxygen Transmitter Introduction appropriate magnetic switch. The LXT-280 uses an "underline" cursor in each of the menus. Figure 1-1 shows the user interface for the LXT-280 instrument. The interface includes the LCD display capable of outputting alphanumeric information in 2 rows of 16 characters per row and 4 magnetic switch arrow keys that control the operation of the unit.

  • Page 14: Model Identification

    • These keys also move the cursor horizontally. 1.5 Model Identification The LXT-280 Transmitter is a 24VDC unit. The instrument is configured at the factory for the customer’s application and so there are many different model designators.

  • Page 15: Installation

    • Configuring the Instrument • Calibration 2.1 Unpacking the Instrument The LXT-280 Transmitter has been carefully packaged to protect it from damage during shipment and dry storage. Upon receipt please follow the procedure outlined below: 1. Before unpacking, inspect the condition of the shipping container to verify proper handling by the carrier.

  • Page 16: Figure 2-1: Typical Installation For The Lxt-280 Transmitter

    YOUR APPLICATION. If mounting hardware is ordered with the instrument, it has been factory assembled and the LXT-280 is ready for mounting. A sunshade should be considered during the selection of the mounting location this prevents direct sunlight from creating an oven effect inside of the enclosure.

  • Page 17: Wiring

    State and Federal requirements. 2.3.2 Power Wiring For power wiring, the LXT-280 transmitter requires a nominal 24- VDC voltage source. With zero loop impedance, the minimum voltage requirement is 14 VDC. The maximum voltage limit is 50 VDC.

  • Page 18: Sensor Wiring

    Installation LXT-280 observe the polarity. Although no damage to the LXT-280 will result from polarity reversal, the instrument will not function. For intrinsically safe wiring see Figure 2-2. CAUTION: DO NOT APPLY 110 VAC TO THE 24 VDC WIRING TERMINALS. DAMAGE TO THE INSTRUMENT WILL RESULT! 2.3.3 Sensor Wiring...

  • Page 19: Configuring The Lxt-280

    Configuring the instrument is described in Section 3 of this manual. 2.5 Calibration Prior to using the instrument for the first time, the LXT-280 must be calibrated. The specific calibration procedure used depends on the application. Among other things, the calibration routine establishes the correspondence between the 4-20 mA output signal and the application dependant measurable parameter.
  • Page 20 Installation LXT-280 Teledyne Analytical Instruments...

  • Page 21: Operation

    This allows instrument operation without having to open the cover and expose the internal parts to the environment. Figure 3-1 shows the layout of the LXT-280 faceplate. Figure 3-1: LXT-280 Operator Interface The operator keys are arranged in two groups: 1.

  • Page 22: Menus

    These keys are also used to move the cursor horizontally. 3.2 Menus The LXT-280 contains a series of menus from which different functions can be accessed. You can scroll through all available menus by activating the VERTICAL ▲ and ▼ keys.

  • Page 23: Contrast

    Display contrast can be adjusted to allow for variations of ambient lighting and viewing angle by using this menu. The Contrast Menu is always located as the uppermost menu. To access the contrast menu from the Main Menu, magnetically activate the UP vertical arrow key once. Contrast Teledyne Analytical Instruments...

  • Page 24: Main Menu

    3.2.2 Main Menu This menu appears after the copyright display when power is first applied to the LXT-280. The MAIN MENU displays the measured process variable, temperature, and the current output in percent of full- scale. While in this menu, the current output can be adjusted and locked in a manual mode to provide an undisturbed output during sensor calibrations.

  • Page 25: Electrode Zero Menu

    The top line displays the buffer, or calibration point, at which the last calibration was performed. The bottom line displays the temperature compensated mV value the electrode generated at the calibration point. Calibration procedures are described in Section 4. Teledyne Analytical Instruments...

  • Page 26: Electrode Span Menu

    The locus is derived by plotting the sensor output versus temperature at different dissolved oxygen concentrations. Empirical data for Teledyne sensors defines the locus to be approximately -17°C. Because dissolved oxygen sensors have different temperature slopes at Teledyne Analytical Instruments...
  • Page 27 25°C. This value should not be changed unless a sensor different than the Teledyne sensor is used. Each sensor manufacturer should define the locus for their sensor.
  • Page 28 Operation LXT-280 Teledyne Analytical Instruments...

  • Page 29: Temperature Calibration Menu Calibration

    4.2 Manual Output Mode In order to perform calibrations without interfering with control or recorder functions, the LXT-280 incorporates a manual output mode. In the manual output mode, the current output is set to the desired level and saved until changed or released from the manual mode. The following procedure demonstrates the use of the manual output.

  • Page 30: Contrast Adjustment

    This "M" signifies that the transmitter output is in manual mode. 3. Magnetically activate the LEFT HORIZONTAL◄ arrow key and observe the "M" disappear, releasing the LXT-280 from the manual output mode. The % output value will return to the real- time current output.

  • Page 31: Zero Calibration

    (near zero), the true oxygen environment is preferred. These two calibration procedures are discussed in detail in the SP-1/SP-2 Sensor Manual. The following procedure describes the steps used to calibrate a DO sensor to the LXT-280 instrument. Procedure: 1. With an instrument magnet, activate the appropriate VERTICAL ▲/▼...

  • Page 32: Span Calibration

    Installation and Maintenance Manual. The following procedure describes the steps used to calibrate the LXT-280 to the sensor. If performing an air span calibration where the unit of measurement is ppm, review Section 5.0, Calibration Correction Factors. This instrument calibration procedure can also be used to calibrate to a sample that has been analyzed through a wet chemical process, such as a Winkler analysis.
  • Page 33 MAY BE CONTAMINATED. SEE SECTION 4.7. Comparing the millivolt values before and after the calibration provides a valuable diagnostic tool in determining the degradation of the electrode. Minor differences in the full scale value is normal; however, Teledyne Analytical Instruments...

  • Page 34: Automatic Buffer Calibration

    4.6 Automatic Buffer Calibration Once the calibration points have been defined in the LXT-280 by performing the zero and span calibration, the Automatic Buffer Calibration feature can be utilized. This feature allows calibrations to be performed without making any adjustments.

  • Page 35: Back-To-Factory Calibration

    Calibration 4.8 Back-to-Factory Calibration This feature allows the LXT-280 to be reset to "nominal electrode" situation. This condition is an electrode with zero millivolts offset at zero percent or ppm oxygen, and a full scale output of –400 mV. This factory calibration feature is very useful in providing a reliable starting point if the instrument has been mis-calibrated.

  • Page 36: Output Calibration

    VERTICAL ▲/▼ arrow key. 6. When the desired value is reached, save the calibration and exit the calibrate mode by magnetically activating the LEFT HORIZONTAL ◄ arrow key until the cursor is all the way to the left. Teledyne Analytical Instruments...

  • Page 37: Locus Calibration

    Dissolved Oxygen Transmitter Calibration 4.10 Locus Calibration As stated in section 3.2.7, the locus value for Teledyne SP-1 and SP-2 sensors is approximately -17.0°C and should not be changed unless a different manufacturer's sensor is used. If the locus is not -17°C, use the following procedure to define the correct locus.

  • Page 38: Temperature Calibration-Manual Tc Adjustment

    The value on the bottom line expresses the real-time process temperature. 4.11.2 Temperature Calibration—Manual TC Adjustment The manual TC feature allows the LXT-280 to operate without a temperature sensor only if the process temperature is known and Teledyne Analytical Instruments...

  • Page 39: Temperature Units Calibration - °C/°F Conversion

    Procedure to adjust manual TC: 1. Place a 3,000 ohm, 1% resistor across terminals TB1-2 and TB1- 5 in place of the sensor wires on the LXT-280 transmitter. 2. Magnetically activate the appropriate VERTICAL ▲/▼ arrow key to reach the Temperature Calibration Menu.
  • Page 40 Calibration LXT-280 Trim° Trim° ° ° Unit 25.0 Unit 77.0 Teledyne Analytical Instruments...

  • Page 41: Calibration Correction Factors

    (if the electrode is being calibrated in solution). 2. Refer to Table 5-1, Oxygen Saturation vs. Temperature and find the solubility value of oxygen in ppm for that temperature. Interpolation may be necessary if the temperature is between the listed values. Record this value. Teledyne Analytical Instruments...

  • Page 42: Table 5-1: Oxygen Saturation Vs. Temperature

    5. Determine the elevation from sea level. 6. Referring to Table 5-3, Elevation Correction Factors, find the intersection of the nearest thousand feet and hundred feet to the elevation at which the calibration is being performed. Record the correction value. Teledyne Analytical Instruments...

  • Page 43: Table 5-2: Relative Humidity Correction Factors

    . 880 .849 .819 .788 .761 .978 .943 .910 .877 .846 .816 .787 .758 .975 .940 .906 .874 .843 .813 .784 .756 .971 .937 .903 .871 .840 .810 .781 .753 .968 .933 .900 .868 .837 .807 .778 .750 Teledyne Analytical Instruments...

  • Page 44: Salinity Correction

    Barometric Pressure of 29.92" Hg (760 mm Hg) Salinity in Correction Salinity in Correction Factor Factor 1.00 0.81 0.98 0.80 0.96 0.78 0.94 0.76 0.92 0.75 0.90 0.73 0.88 0.70 0.86 0.66 0.85 0.63 0.83 0.60 Teledyne Analytical Instruments...

  • Page 45: Calibration Example

    (Winkler analysis) or by using a laboratory electrode. After determining the dissolved oxygen concentration by one of these methods, the SP-1 or SP-2 can be standardized to that value. Teledyne Analytical Instruments...

  • Page 46: Dissolved Oxygen Units Of Measurement

    100% in air or an oxygen rich environment. Subsequent measurements are an indication of oxygen consumption. This unit of measurement is typically used in environments that must be oxygen-rich, such as bioreactors, fermenters and waste-water aeration basins. Teledyne Analytical Instruments...

  • Page 47: Maintenance

    6.1.2 Replacement of the Microprocessor: For replacement of the microprocessor, contact the factory . CAUTION: NEVER INTERCHANGE EPROMS FROM ONE TRANSMITTER TO ANOTHER. DOING SO WILL AFFECT TRANSMITTER PERFORMANCE. Teledyne Analytical Instruments...

  • Page 48: Table 6-1: Troubleshooting

    Air bubble is trapped in from the sensor body and front of the electrode. shake air bubble away from the membrane. Check the sensor position with respect to horizontal. Make sure air is not trapped in the guard. Teledyne Analytical Instruments...
  • Page 49 Clean the membrane. See Coated membrane Sensor manual. Verify instrument calibration. Electrode cartridge is not Check electrode cartridge fully engaged in the sensor to see that it is fully body engaged in sensor body Teledyne Analytical Instruments...
  • Page 50 The DO reading is over- Verify the correct locus. If The locus point is not sensitive or under-sensitive using Teledyne sensors, correct with temperature changes. the locus must be -17°C. A troubleshooting procedural recommendation: In troubleshooting an analytical measurement loop, it should be kept in mind that the majority of the problems encountered with the measurement are due to failures of the sensing element.

  • Page 51: Appendix

    Ranges: 0-200 % fully expandable and reversible. 0-20 ppm. Response Time: 90% of step change in 1 second Accuracy: ±0.10% of full scale Linearity: ±0.05% of full scale Sensitivity: ±0.01 ppm ±0.1 percent saturation Stability: ±0.2% per year @ 0 to 70°C Teledyne Analytical Instruments...
  • Page 52 Temperature Trim Allows for compensation for any differences in RTDs by programming the offset to the transmitter. Temperature Display Temperature can be field-configured to display in °C or °F. Teledyne Analytical Instruments...

  • Page 53: Spare Parts Listing

    Terminal Screw and Clamp Assembly, set of 9 ECD-9680044.1 Instrument Screwdriver with Magnetic Top Note: In order to provide replacement proms for the LXT-280, the transmitter serial number and the software serial number are needed. The transmitter serial number is located on the serial number tag located inside the instrument.
  • Page 54 Appendix LXT-280 the instrument for which the parts are intended. Orders should be sent to: TELEDYNE Analytical Instruments 16830 Chestnut Street City of Industry, CA 91749-1580 Phone (626) 934-1500, Fax (626) 961-2538 Web: www.teledyne-ai.com or your local representative. Teledyne Analytical Instruments...

  • Page 55: Index

    DO locus menu, 16 magnetic screwdriver, 11 effective range, 14, 15 magnetic switch, 1, 2, 11 electrode, 8, 14 main menu, 14 electrode data screen, 14 manual mode, 9, 14, 19 electrode degradation, 23 manual temperature compensation, 28 Teledyne Analytical Instruments...
  • Page 56 1, 15 sunshade, 6 percent oxygen saturation, 36 tables listing, ix percent solubility, 36 technician symbol, iv pH, 1 Teledyne address, 44 pipe mount, 5 temperature, 14 polarity, 8 temperature calibration, 19 power, 1, 8, 41 temperature calibration screen, 27, 29...
  • Page 57 5 window, 2, 11 warning sign, iv Winkler analysis, 22 warranty, ii zero calibration, 15, 19, 21 weather-proof enclosure, 41 zero electrode offset, 2 web address, 44 zero offset, 15 website address, v zero simulation, 21 Teledyne Analytical Instruments...

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