Table of Contents
Advertisement
OPERATING INSTRUCTIONS
Model 235 Series
THERMAL CONDUCTIVITY ANALYZER
HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS MONITORING SYSTEM.
PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM.
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
Thermal Conductivity Analyzer
FOR
235
236
237
238
DANGER
P/N M32845
08/06/99
ECO # 99-0323
i
Advertisement
Table of Contents
Related Manuals for Teledyne 235
Summary of Contents for Teledyne 235
-
Page 1: Operating Instructions
Thermal Conductivity Analyzer OPERATING INSTRUCTIONS Model 235 Series THERMAL CONDUCTIVITY ANALYZER DANGER HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS MONITORING SYSTEM. PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM. HAZARDOUS VOLTAGES EXIST ON CERTAIN COMPONENTS INTERNALLY WHICH MAY PERSIST FOR A TIME EVEN AFTER THE POWER IS TURNED OFF AND DISCONNECTED. - Page 2 Any safeguards required such as locks, labels, or redun- dancy, must be provided by the user or specifically requested of Teledyne at the time the order is placed.
-
Page 3: Table Of Contents
Thermal Conductivity Analyzer Table of Contents 1 Introduction (Models 235, 236, 237, 238) 1.1 Electronic Circuitry ............1-2 1.2 Plug-in Circuit Boards ..........1-3 1.2.1 T.C. Cell Power Supply/Amplifier Board ... 1-3 1.2.2 Differential Power Supply Board ....... 1-3 1.2.3 Alarm Comparator Board (optional) ....1-3 1.2.4 E to I Converter Board (optional) ...... - Page 4 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 5: Introduction (Models 235, 236, 237, 238)
Introduction 1 Introduction (Models 235, 236, 237, 238) The 235 Series Thermal Conductivity Analyzers measure the concen- tration of one component in a binary stream of gas, or the purity of a sample stream containing a composite mixture of impurities, by comparing the difference in thermal conductivity of the sample stream with that of a reference gas of fixed composition. -
Page 6: Electronic Circuitry
Explosion-proof models of the series use sealed explosion-proof enclosures for the analysis section (Model 237) or both the analysis section and control unit (Model 238). Model 235 is general purpose with remote control unit, and Model 235 is general purpose with integral control unit. -
Page 7: Plug-In Circuit Boards
Power failure or “fail-safe” alarming can also be provided. Refer to the specifications covering one individual analyzer for details regarding specific alarm or other optional provisions. Teledyne Analytical Instruments... -
Page 8: E To I Converter Board (Optional)
An excellent alternative to the use of correction curves is available as an option with the Series 235 Analyzer. A digital linearizer circuit is avail- able as a plug-in PC board. This is a very flexible circuit that produces a linear correction to a wide variety of non-linear curves. -
Page 9: Installation
A solid water-pipe ground should be provided for personnel protection. When connecting the power source, polarize the connections as indicated on the interconnection diagram at the rear of the manual. Teledyne Analytical Instruments... -
Page 10: Gas Connections
2 Installation Model 235 Series Use 2-conductor shielded cable (nominally No. 22 wire size) to inter- connect the analyzer output signal with the recording equipment. The shield should be terminated on the appropriate terminal (see interconnection diagram) at the analyzer—and be left disconnected at the recorder. -
Page 11: Vent Lines
Air trapped during assembly can, and will, diffuse back into the cylinder. This is particularly important in applications where impurities of 1 and 2% are the range of interest. Teledyne Analytical Instruments... -
Page 12: Accessory Sample System Components
2 Installation Model 235 Series Accessory Sample System Components An integral gas selector panel is available as an option. This panel mounts the gas controls on a panel where they can be operated conveniently In applications where TBE furnishes an accessory gas control panel, or... - Page 13 For example, for hydrogen or helium, set the flowmeter reading to 0.1 SCFH. A higher reading is recommended for heavier-than- air gas backgrounds, e.g., for carbon dioxide or argon, set the flowmeter to 0.4 SCFH. Teledyne Analytical Instruments...
- Page 14 2 Installation Model 235 Series Teledyne Analytical Instruments...
-
Page 15: Operation
DO NOT allow this screw to be readjusted after the zero-standardization has been performed. No mechanical zero is used with digital meters. Teledyne Analytical Instruments... -
Page 16: Span Standardization
3 Operation Model 235 Series 1. Check to see that the span control is set at about 50% of its travel. Some readjustment of this control may be necessary during standardization, but our concern at this point is to see that a reasonable level of output signal is available to the recorder for zero standardization. -
Page 17: Normal Operation
Since there are no moving parts in the analyzer, no routine mainte- nance is required other than normal care of the instrument. The checklist above should be adequate to keep the analyzer functioning properly for many years. Teledyne Analytical Instruments... - Page 18 3 Operation Model 235 Series Teledyne Analytical Instruments...
-
Page 19: Linearizer
P2. In this case, its output is added to the output of the first amp. The total gain (the slope of the line segment) for the combined segment is now about 1.9. TELEDYNE BROWN ENGINEERING Analytical Instruments... - Page 20 4 Linearizer Model 235 Figure 4-1a: THE PROBLEM The analyzer output is not directly proportional to the parameter it is supposed to measure. Figure 4-1b: THE SOLUTION The Linearizer output is proportional to its input in a complimentary fashion to the analyzer curve. As a result, the output is directly proportional to the parameter being measured.
- Page 21 Adjust the gain of the first amplifier to bring the first segment (from 0 to 1) of the analyzer curve into line with the ideal curve. This produces a small error in the first section, but a larger error at higher inputs. TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 22 4 Linearizer Model 235 Figure 4-2b: THE IMPLEMENTATION - STEP 2 At point 1, the second amplifier begins to work in addition to the first. Its gain is adjusted so that point 2 lies on the ideal curve. The error is small until point 2 is reached.
- Page 23 FIGURE 4-2c: THE IMPLEMENTATION - STEP 3 At point 2, the third amplifier begins to work in addition to the first two. Its gain is adjusted so that point 3 lies on the ideal curve. TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 24 4 Linearizer Model 235 Figure 4-3: THE RESULT By using all the line segment amplifiers, the output of the analyzer is made to be almost directly proportional to the parameter being measured. TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 25 Thermal Conductivity Analyzer Linearizer 4 Figure 4-4: The Effect of Each Amplifier on the Final Result The points labeled 1, 2, 3, etc. are breakpoints. TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 26 4 Linearizer Model 235 Figure 4-5: Exaggerated Illustration of How the Linearizer Works TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 27 The gain for this amplifier may be set between 0 and 4. The other line segment amplifiers work in a similar fashion. Let us examine A1C, for example. Refer to Figure 4-7 for the following analysis of a typical line segment amplifier. TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 28 4 Linearizer Model 235 Figure 4-6: Output of Linearizer on Oscilloscope Screen Using Triangle Wave Notice the mirror image effect as the voltage comes down from its maximum. If the vertical scale and the timebase are arranged so that the slope of the...
- Page 29 -R20 (V /R7-15/R6) > O From this it can be seen that the circuit amplifies input voltages above a cutoff voltage, and otherwise has zero output. -R20 (V /R7-15/R6) = O = 15 x R7/R6 TELEDYNE BROWN ENGINEERING 4-11 Analytical Instruments...
- Page 30 4 Linearizer Model 235 The negative supply voltage is -15 Volts. A similar expression for the output is V = -4(V cutoff Notice that V is actually 2.5 times the voltage at the linearizer input, due to the gain of AlA. This gain acts to minimize the effect of offset errors.
- Page 31 The resistors for the breakpoints are set according to the formula: R = 299.4/V bkpt where V is the voltage at the particular breakpoint. bkpt The resistors affected are R6, R8, R10, R12, R14, R16 and R18 where R6 is the first breakpoint. TELEDYNE BROWN ENGINEERING 4-13 Analytical Instruments...
- Page 32 4 Linearizer Model 235 Figure 4-8: A Simple Curve 4-14 TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 33 Thermal Conductivity Analyzer Linearizer 4 Figure 4-9: An “S” Shaped Curve TELEDYNE BROWN ENGINEERING 4-15 Analytical Instruments...
- Page 34 4 Linearizer Model 235 Figure 4-10: Typical Component Placement on Linearizer 4-16 TELEDYNE BROWN ENGINEERING Analytical Instruments...
- Page 35 0 volts as well. Make V (1) per chart. This is the first breakpoint test voltage. NOTE: V must always be positive. Adjust P1 until V (1) per chart. NOTE: make sure P1 changes V TELEDYNE BROWN ENGINEERING 4-17 Analytical Instruments...
- Page 36 4 Linearizer Model 235 Make V (2) per chart. This is the second test breakpoint voltage. Adjust P2 until V (2). Continue up each line segment, repeating the procedures of the sections just covered, using pots P3, P4, P5, P6, P7, and P8, to linearize line segments 3, 4, 5, 6, 7, and 8.
-
Page 37: Appendix
IMPORTANT: Orders for replacement parts should include the part number, the model, and serial numbers of the analyzer in which they are to be used. 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 TWX (910) 584-1887 TDYANYL COID Web: www.teledyne-ai.com... -
Page 38: Calibration Data
Appendix Model 235 Calibration Data The following data, along with any Addenda that may be included in the front part of this manual, pertain to your specific Thermal Conductivity Analyzer. Calibration data for Model: ______________________ Serial Number: ______________________ Range: ______________________...