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Related Manuals for Fluke 7341
Summary of Contents for Fluke 7341
- Page 1 Hart Scientific 7341 Calibration Bath User’s Guide Rev. 681504...
- Page 2 Limited Warranty & Limitation of Liability Each product from Fluke's Hart Scientific Division ("Hart") is warranted to be free from defects in mate- rial and workmanship under normal use and service. The warranty period is one year for the Calibration Bath.
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Page 3: Table Of Contents
Table of Contents 1 Before You Start ......1 Symbols Used ......1 Safety Information . - Page 4 Front Control Panel ......23 Refrigeration Condenser Access Door ....24 Bath Tank and Lid .
- Page 5 9.6.3 Program Soak Time ....... 43 9.6.4 Program Function Mode ......44 9.6.5 Program Control .
- Page 6 11 Calibration Procedure ..... . 65 11.1 Calibration Points ......65 11.2 Measuring the Set-point Error.
- Page 7 Figures Figure 1 Stir Baffle Fill Levels ......14 Figure 2 Tipping Prevention Bracket Installation ....18 Figure 3 Front Control Panel .
- Page 8 Tables Table 1 International Electrical Symbols ..... 1 Table 2 Table of Various Bath Fluids and Their Properties... . 32 Table 3 Program Mode Setting Actions .
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Page 9: Before You Start
1 Before You Start Symbols Used Before You Start Symbols Used Table 1 lists the International Electrical Symbols. Some or all of these symbols may be used on the instrument or in this manual. Table 1 International Electrical Symbols Symbol Description AC (Alternating Current) AC-DC... -
Page 10: Safety Information
7341 Calibration Bath User’s Guide Symbol Description C-TIC Australian EMC mark The European Waste Electrical and Electronic Equipment (WEEE) Directive (2002/96/EC) mark. Safety Information Use this instrument only as specified in this manual. Otherwise, the protection provided by the instrument may be impaired. Refer to the safety information in Warnings and Cautions sections. - Page 11 1 Before You Start Safety Information • DO NOT operate high temperature baths (500°C) near flammable materi- als. Extreme temperatures could ignite the flammable material. • Overhead clearance is required. Do not place the instrument under a cabi- net or other structure. Always leave enough clearance to allow for safe and easy insertion and removal of probes.
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Page 12: Cautions
7341 Calibration Bath User’s Guide • High voltage is used in the operation of this equipment. Severe injury or death may result if personnel fail to observe the safety precautions. Before working inside the equipment, turn off the power and disconnect the power cord. -
Page 13: Authorized Service Centers
Voltage Cut In: ±7.5% (213 - 247 VAC) Authorized Service Centers Please contact one of the following authorized Service Centers to coordinate service on your Hart product: Fluke Corporation, Hart Scientific Division 799 E. Utah Valley Drive American Fork, UT 84003-9775 Phone: +1.801.763.1600... - Page 14 22 Jianguomenwai Dajie Chao Yang District Beijing 100004, PRC CHINA Phone: +86-10-6-512-3436 Telefax: +86-10-6-512-3437 E-mail: xingye.han@fluke.com.cn Fluke South East Asia Pte Ltd. Fluke ASEAN Regional Office Service Center 60 Alexandra Terrace #03-16 The Comtech (Lobby D) 118502 SINGAPORE Phone: +65 6799-5588 Telefax: +65 6799-5588 E-mail: antng@singa.fluke.com...
- Page 15 1 Before You Start Authorized Service Centers • Serial Number • Voltage • Complete description of the problem...
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Page 16: Introduction
Digital remote communications is standard with an RS-232 and optional with an IEEE-488 interface. The 7341 bath was designed to be compact and low cost without compromising performance. The 7341 bath operates over a wide temperature range from –40°C to 150°C. The refrigeration permits sub-ambient temperature control. -
Page 17: Specifications And Environmental Conditions
3 Specifications and Environmental Conditions Specifications Specifications and Environmental Conditions Specifications Range –45°C to 150°C Stability (2 sigma) ±0.005°C at –40°C (ethanol) ±0.005°C at 25°C (water) ±0.007°C at 150°C (5012 oil) Uniformity ±0.007°C at –40°C (ethanol) ±0.007°C at 25°C (water) ±0.010°C at 150°C (5012 oil) Heating Time †... -
Page 18: Environmental Conditions
7341 Calibration Bath User’s Guide Environmental Conditions Although the instrument has been designed for optimum durability and trou- ble-free operation, it must be handled with care. The instrument should not be operated in an excessively dusty or dirty environment. Maintenance and clean- ing recommendations can be found in the Maintenance Section of this manual. -
Page 19: Quick Start
Unpack the bath carefully and inspect it for any damage that may have oc- curred during shipment. If there is shipping damage, notify the carrier immedi- ately. Verify that all components are present: • 7341 Bath • Access Hole Cover • Fluid Expansion Reservoir with Cover •... -
Page 20: Figure 1 Stir Baffle Fill Levels
7341 Calibration Bath User’s Guide Set up of the bath requires careful unpacking and placement of the bath, filling the bath with fluid, and connecting power. Consult Section 5, Installation, for detailed instructions for proper installation of the bath. Be sure to place the bath in a safe, clean and level location. -
Page 21: Power
4 Quick Start Power An overflow drain is provided for excess bath fluid due to expansion. This drains the fluid into the fluid expansion reservoir for reuse. See Section 7.4.1, Fluid Expansion Reservoir, for details in using the reservoir. Note: As the temperature of the bath increases the fluid level will increase, see Section 6 on page 21. - Page 22 7341 Calibration Bath User’s Guide Increment display New set-point value C 30.00 Press SET to accept the new value and display the vernier value. The bath be- gins heating or cooling to the new set-point. Store new set-point, access vernier Current vernier value 0.00000...
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Page 23: Installation
Personal injury or damage to the bath may occur. Bath Environment The Model 7341 Bath is a precision instrument, which should be located in an appropriate environment. The location should be free of drafts, extreme temper- atures and temperature changes, dirt, etc. The surface where the bath is placed must be level. -
Page 24: Installation On A Wood Floor
7341 Calibration Bath User’s Guide 5.3.1 Installation On A Wood Floor The wood floor installation kit includes lag bolts. Drill three 1/8 inch x 1 inch deep (approximately 3 mm x 25.5 mm) pilot holes using the tipping bracket to mark the hole placement. -
Page 25: Dry-Out" Period
Cover the panel if necessary during filling. DO NOT over- fill. The Model 7341 Bath is not provided with a fluid. Various fluids are available from Hart Scientific and other sources. Depending on the desired temperature range, any of the following fluids, as well as others, may be used in the bath: •... -
Page 26: Power
7341 Calibration Bath User’s Guide Be sure the fluid expansion reservoir is properly installed checking to insure it is clean and free of foreign matter. Carefully monitor the bath fluid level as the bath temperature rises to prevent excessive overflow or splashing. Remove ex- cess hot fluid if necessary with caution. -
Page 27: Bath Use
6 Bath Use General Bath Use CAUTION: Read this section entitled BATH USE before placing the bath in service. The information in this section is for general information only. It is not de- signed to be the basis for calibration laboratory procedures. Each laboratory needs to write their specific procedures. -
Page 28: Calibration Of Multiple Probes
7341 Calibration Bath User’s Guide tion. The fluid in the bath allows different types of probes to be calibrated at the same time. However, stem effect from different types of probes is not to- tally eliminated. Even though all baths have horizontal and vertical gradients, these gradients are minimized inside the bath work area. -
Page 29: Parts And Controls
7 Parts and Controls Front Control Panel Parts and Controls Front Control Panel The following controls and indicators are present on the controller front panel (see Figure 3 below): (1) the digital LED display, (2) the control buttons, (3) the bath on/off power switch, (4) the control indicator light, and (5) the cooling on/off switch. -
Page 30: Refrigeration Condenser Access Door
7341 Calibration Bath User’s Guide 5. The cooling switch turns on the refrigeration for control below 50°C and rapid cool down. The cooling shuts off automatically above 60°C. Manually turn off the refrigeration at temperatures where it has been determined to be un- necessary. -
Page 31: Back Panel
7 Parts and Controls Back Panel Back Panel On the back of the bath are the system fuses, power cord, high/low voltage in- dicator, drain, serial port, IEEE-488 port (if installed), and the fluid expansion reservoir. 7.4.1 Fluid Expansion Reservoir The fluid expansion reservoir is attached to the rear panel of the bath. -
Page 32: General Operation
Heat Transfer Fluid General Operation Heat Transfer Fluid Many fluids will work with 7341 bath. Choosing a fluid requires consideration of many important characteristics of the fluid. Among these are temperature range, viscosity, specific heat, thermal conductivity, thermal expansion, electri- cal resistivity, fluid lifetime, safety, and cost. -
Page 33: Thermal Conductivity
7341 Calibration Bath User’s Guide proportional band may require some adjustment depending on the specific heat of the fluid. 8.1.4 Thermal Conductivity Thermal conductivity measures how easily heat flows through the fluid. Ther- mal conductivity of the fluid affects the control stability, temperature unifor- mity, and temperature settling time. -
Page 34: Electrical Resistivity
8 General Operation Heat Transfer Fluid Ending temperature, T = 300°C Starting temperature, T = 25°C Ending depth, D = 9.2 inches = 9.2/[0.00077 (300-25) + 1] = 7.59 inches 8.1.6 Electrical Resistivity Electrical resistivity describes how well the fluid insulates against the flow of electric current. -
Page 35: Cost
7341 Calibration Bath User’s Guide 8.1.9 Cost Cost of bath fluids may vary greatly, from cents per gallon for water to hun- dreds of dollars per gallon for synthetic oils. Cost may be an important consid- eration when choosing a fluid. -
Page 36: Silicone Oil
8 General Operation Heat Transfer Fluid 8.1.10.4 Silicone Oil Silicone oils are available which offer a much wider operating temperature range than mineral oil. Like most oils, silicone oils have temperature control characteristics, which are somewhat poorer than water. The viscosity changes significantly with temperature and thermal expansion also occurs. -
Page 37: Table 2 Table Of Various Bath Fluids And Their Properties
7341 Calibration Bath User’s Guide Table 2 Table of Various Bath Fluids and Their Properties Fluid Lower Upper Thermal Thermal (# = Hart Part No.) Temperature Temperature Flash Viscosity Specific Specific Heat Conductivity Expansion Resistivity Ω-cm ) Limit* Limit* Point... -
Page 38: Figure 4 Chart Of Various Bath Fluids And Their Properties
8 General Operation Heat Transfer Fluid –100°C 0°C 100°C 200°C 300°C 400°C 500°C 600°C Silicone Oil FL 302°C 10 CS 5017 Silicone Oil FL 280°C 10 CS 5014 Silicone Oil FL 232°C 10 CS 5013 Silicone Oil FL 211°C 10 CS 5012 Silicone Oil FL 133°C... -
Page 39: Stirring
7341 Calibration Bath User’s Guide Flash Point: The point at which ignition may occur. The point shown may be either the open or closed cup flash point. Refer to the flash point discussion in Section 8.1.8, Safety. Boiling Point: At or near the boiling point of the fluid the temperature stability is difficult to maintain. -
Page 40: Temperature Controller
8 General Operation Temperature Controller Temperature Controller Hart Scientific’s unique hybrid digital/analog temperature controller controls the bath temperature. The controller offers the tight control stability of an ana- log temperature controller as well as the flexibility and programmability of a digital controller. - Page 41 7341 Calibration Bath User’s Guide When the bath is controlling at temperatures between the 60°C and 0°C, the bath operates in a low cooling capacity mode with the hot gas bypass valve on (HGb on). The HGb system reduces the cooling capacity and helps to improve the bath stability within that temperature range.
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Page 42: Controller Operation
9 Controller Operation Bath Temperature Controller Operation This chapter discusses in detail how to operate the bath temperature controller using the front control panel. Using the front panel key switches and LED dis- play the user may monitor the bath temperature, set the temperature set-point in degrees C or F, monitor the heater output power, adjust the controller propor- tional band, set the cutout set-point, and program the probe calibration parame- ters, operating parameters, serial and IEEE-488 interface configuration, and... -
Page 43: Figure 5 Controller Operation Flowchart
7341 Calibration Bath User’s Guide Figure 5 Controller Operation Flowchart... -
Page 44: Temperature Set-Point
9 Controller Operation Temperature Set-point rESEt ? Cutout reset function Press “SET” once more to reset the cutout. Reset cutout This action switches the display to the set temperature function. To return to displaying the temperature display press the “EXIT” button. If the cutout is still in the over-temperature fault condition, the display continues to flash “cutout”. -
Page 45: Set-Point Value
7341 Calibration Bath User’s Guide Accept selected set-point memory 9.3.2 Set-point Value After selecting the set-point memory and pressing “SET”, the set-point value may be adjusted in increments of 0.01° (C or F). The set-point value is dis- played with the units, C or F, at the left. -
Page 46: Scan
9 Controller Operation Scan Next press “EXIT” to return to the temperature display or “SET” to access the temperature scale units selection. Access scale units Scan The scan rate can be set and enabled so that when the set-point is changed the instrument heats or cools at a specified rate (degrees per minute) until it reaches the new set-point. -
Page 47: Temperature Scale Units
7341 Calibration Bath User’s Guide Temperature Scale Units The temperature scale units of the controller may be set by the user to degrees Celsius (°C) or Fahrenheit (°F). The units are used in displaying the bath tem- perature, set-point, vernier, proportional band, and cutout set-point. -
Page 48: Set-Points
9 Controller Operation Ramp and Soak Program set-points are independent from the programmable set-points described in Sec- tion 9.3.1, Programmable Set-points. Number of program set-points Pn=8 Use the “UP” or “DOWN” buttons to change the number from 2 to 8. Pn=3 New number of program set-points Press “SET”... -
Page 49: Program Function Mode
7341 Calibration Bath User’s Guide Pt=5 New soak time Press “SET” to continue. Save new setting 9.6.4 Program Function Mode The next parameter is the program function or cycle mode. There are four pos- sible modes which determine whether the program scans up (from set-point 1 to n) only or both up and down (from set-point n to 1), and also whether the program stops after one cycle or repeats the cycle indefinitely. -
Page 50: Secondary Menu
9 Controller Operation Secondary Menu Press “SET” to activate the new program control command and return to the temperature display. Activate new command Secondary Menu Functions, which are used less often, are accessed within the secondary menu. The secondary menu is accessed by pressing “SET” and “EXIT” simulta- neously and then releasing. -
Page 51: Figure 6 Bath Temperature Fluctuation At Various Proportional Band Settings
7341 Calibration Bath User’s Guide The temperature stability of the bath depends on the width of the proportional band (see Figure 6). If the band is too wide, the bath temperature deviates ex- cessively from the set-point due to varying external conditions. This is because the power output changes very little with temperature and the controller cannot respond very well to changing conditions or noise in the system. -
Page 52: Table 4 Typical Proportional Band Settings For Various Fluids
9 Controller Operation Proportional Band tional band settings for optimum performance with a variety of fluids at se- lected temperatures. Table 4 Typical Proportional Band Settings for Various Fluids Fluid Temperature Proportional Band Stability Water 30°C 0.31°C ±0.003°C Water 60°C 0.31°C ±0.003°C Eth-Gly 50%... -
Page 53: Cutout
7341 Calibration Bath User’s Guide 9.10 Cutout As a protection against software or hardware fault, shorted heater triac, or user error, the bath is equipped with an adjustable heater cutout device that shuts off power to the heater if the bath temperature exceeds a set value. This protects... -
Page 54: Controller Configuration
9 Controller Operation Controller Configuration To accept the new cutout set-point press “SET”. Accept cutout set-point The next function is the configuration menu. Press “EXIT” to resume display- ing the bath temperature. 9.11 Controller Configuration The controller has a number of configuration and operating options and calibra- tion parameters, which are programmable via the front panel. -
Page 55: Operating Parameters
7341 Calibration Bath User’s Guide 9.13 Operating Parameters The operating parameters menu is accessed by pressing “UP” when the probe menu is displayed. The operating parameters menu is indicated by, Operating parameters menu Press “UP” to enter the menu. The operating parameters menu contains the cut- out reset mode parameter, cooling mode, and hot gas bypass mode. -
Page 56: Hot Gas Bypass Mode
9 Controller Operation Operating Parameters CooL Cooling mode parameter Press “SET” to access the parameter setting. Cooling mode set for automatic Auto To change to On or Off mode, press “DOWN” until the desired mode appears and then press “SET”. Cooling mode set to on Cooling mode set to off Individual steps may be skipped by pressing “EXIT”... -
Page 57: Serial Interface Parameters
7341 Calibration Bath User’s Guide 9.14 Serial Interface Parameters The serial interface menu is accessed by pressing “UP” from the operating pa- rameters menu. The serial RS-232 interface parameters menu is indicated by, Serial RS-232 interface parameters menu SErIAL The serial interface parameters menu contains parameters which determine the operation of the serial interface. -
Page 58: Duplex Mode
9 Controller Operation Serial Interface Parameters SA= 1 Current sample period (seconds) Adjust the value with “UP” or “DOWN” and then use “SET” to set the sample rate to the displayed value. SA= 60 New sample period 9.14.3 Duplex Mode The next parameter is the duplex mode. -
Page 59: Ieee-488 Parameters
7341 Calibration Bath User’s Guide 9.15 IEEE-488 Parameters Baths may optionally be fitted with an IEEE-488 GPIB interface. In this case the user may set the interface address and the transmission termination charac- ter within the IEEE-488 parameter menu. This menu does not appear on baths not fitted with the interface. -
Page 60: Calibration Parameters
9 Controller Operation Calibration Parameters Use “SET” to save the new selection. 9.16 Calibration Parameters The operator of the bath controller has access to a number of the instrument calibration constants namely CTO, C0, CG, H, L, and HGbt. These values are set at the factory and must not be altered. -
Page 61: Digital Communication Interface
Serial Communications Digital Communication Interface The 7341 bath is capable of communicating with and being controlled by other equipment through the digital interface. Two types of digital interface are avail- able - the RS-232 serial interface which is standard and the IEEE-488 GPIB in- terface which is optional. -
Page 62: Wiring
7341 Calibration Bath User’s Guide 10.1.1 Wiring The serial communications ca- ble attaches to the bath through the DB-9 connector on the back of the instrument. Figure 7 shows the pin-out of this con- nector and the suggested cable wiring. To eliminate noise, the... -
Page 63: Duplex Mode
10 Digital Communication Interface IEEE-488 Communication (optional) ature measurements transmitted from the serial interface. If the sample period is set to 5, the bath transmits the current measurement over the serial interface approximately every five seconds. The automatic sampling is disabled with a sample period of 0. -
Page 64: Ieee-488 Address
7341 Calibration Bath User’s Guide IEEE-488 interface menu is indicated with “IEEE”. Press “SET” to enter the IEEE-488 parameter menu. 10.2.1.1 IEEE-488 Address The IEEE-488 address is indicated with “AddrESS”. Press “SET” to program the address. The default address is 22. Change the device address of the bath if necessary to match the address used by the communication equipment by pressing “UP”... -
Page 65: Cooling Control
Cooling Control 10.4 Cooling Control The 7341 bath has a fully automated refrigeration control system when the cooling power switch on the front panel is activated. Under normal conditions, the refrigeration is on at any temperature below approximately 60°C (see Sec- tion 8.6, Refrigeration). -
Page 66: Table 5 Interface Command Summary
7341 Calibration Bath User’s Guide Table 5 Interface Command Summary Command Command Returned Command Description Format Example Returned Example Acceptable Values Display Temperature Read current set-point s[etpoint] set: 9999.99 {C set: 150.00 C or F} Set current set-point to n... - Page 67 10 Digital Communication Interface Cooling Control Interface Command Summary Continued Command Command Returned Command Description Format Example Returned Example Acceptable Values Secondary Menu Read proportional band setting pr[op-band] pr: 9.999 pr: 0.326 Set proportional band to n pr[op-band]=n pr=0.326 Depends on Configuration Read cutout setting c[utout]...
- Page 68 7341 Calibration Bath User’s Guide Interface Command Summary Continued Command Command Returned Command Description Format Example Returned Example Acceptable Values Set Cool mode to On co[ol]=on co=on Set Cool mode to Auto co[ol]=au[to] co=au Read HGb mode hg[b] hgb:xxx hgb: auto...
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Page 69: Calibration Procedure
11 Calibration Procedure Calibration Points Calibration Procedure In some instances the user may want to calibrate the bath to improve the tem- perature set-point accuracy. Calibration is done by adjusting the controller probe calibration constants R0 and ALPHA so that the temperature of the bath as measured with a standard thermometer agrees more closely with the bath set-point. -
Page 70: Calibration Example
7341 Calibration Bath User’s Guide the old values for R0 and ALPHA, the calibration temperature set-points t , and the temperature errors err and err into the following equations, ⎡ ⎤ − err t err t ′ = ⎢ ALPHA ⎥... -
Page 71: Figure 8 Calibration Example
11 Calibration Procedure Calibration Example R0 = 100.000 ALPHA = 0.0038500 = 30.00°C measured t = 29.843°C = 80.00°C measured t = 79.914°C Compute errors, = 29.843 - 30.00°C = -0.157°C = 79.914 - 80.00°C = -0.086°C Compute R0′, ⎡ ( ⎤... -
Page 72: Maintenance
12 Maintenance Maintenance The calibration instrument has been designed with the utmost care. Ease of op- eration and simplicity of maintenance have been a central theme in the product development. Therefore, with proper care the instrument should require very little maintenance. Avoid operating the instrument in dirty or dusty environments. - Page 73 7341 Calibration Bath User’s Guide dust does not build up on the fins hampering the efficiency of the bath, i.e. month, bi-monthly. Use a vacuum or cloth to clean the fins. • If a hazardous material is spilt on or inside the equipment, the user is re- sponsible for taking the appropriate decontamination steps as outlined by the national safety council with respect to the material.
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Page 74: Troubleshooting
13 Troubleshooting Troubleshooting Troubleshooting This section contains information on troubleshooting, CE Comments, and a wiring diagram. This information pertains to a number of bath models and cer- tain specifics may not pertain to your model. 13.1 Troubleshooting In the event that the instrument appears to function abnormally, this section may help to find and solve the problem. - Page 75 7341 Calibration Bath User’s Guide Problem Causes and Solutions The display flashes “cutout” and The problem may be that the controller’s voltmeter circuit is not func- an incorrect process temperature tioning properly. • A problem could exist with the memory back-up battery.
- Page 76 13 Troubleshooting Troubleshooting Problem Causes and Solutions The controller controls or at- The controller operates normally except when controlling at a speci- tempts to control at an inaccurate fied set-point. At this set-point, the temperature displayed does not temperature agree with the temperature measured by the user’s reference ther- mometer to within the specified accuracy.
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Page 77: Comments
7341 Calibration Bath User’s Guide Problem Causes and Solutions The controller erratically heats If both the bath temperature and output power do not vary periodically then cools, control is unstable but in a very erratic manner, the problem may be excess noise in the system. -
Page 78: Emission Testing
13 Troubleshooting Comments 13.2.1.2 Emission Testing The instrument fulfills the limit requirements for Class A equipment but does not fulfill the limit requirements for Class B equipment. The instrument was not designed to be used in domestic establishments. 13.2.2 Low Voltage Directive (Safety) In order to comply with the European Low Voltage Directive (73/23/EEC), Hart Scientific equipment has been designed to meet the IEC 1010-1 (EN 61010-1) and the IEC 1010-2-010 (EN 61010-2-010) standards.
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