Page 1
Hart Scientific
9141
Dry-Well Calibrator
User’s Guide
Rev. 5B0702
Page 2
Fluke Corporation, Hart Scientific Division
799 E. Utah Valley Drive • American Fork, UT 84003-9775 • USA
Phone: +1.801.763.1600 • Telefax: +1.801.763.1010
E-mail: support@hartscientific.com
www.hartscientific.com
Subject to change without notice. • Copyright © 2005 • Printed in USA
Rev. 5B0702
Page 3
Table of Contents
1 Before You Start . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 WARNINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.2 CAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Authorized Service Centers. . . . . . . . . . . . . . . . . . . . . . 6
2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3 Specifications and Environmental Conditions . . . . . . . . . 11
3.1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Environmental Conditions. . . . . . . . . . . . . . . . . . . . . . 11
3.3 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4 Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2 Set-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4 Setting the Temperature . . . . . . . . . . . . . . . . . . . . . . . 14
5 Parts and Controls . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Bottom Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 Constant Temperature Block Assembly . . . . . . . . . . . . . . . 17
5.3.1 Constant Temperature Block . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3.2 Probe Sleeves and Tongs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6 General Operation . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1 Changing Display Units . . . . . . . . . . . . . . . . . . . . . . . 19
6.2 Switching to 230V Operation . . . . . . . . . . . . . . . . . . . . 19
7 Controller Operation . . . . . . . . . . . . . . . . . . . . . . . 21
7.1 Well Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.2 Temperature Set-point . . . . . . . . . . . . . . . . . . . . . . . . 21
7.2.1 Programmable Set-points . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.2.2 Set-point Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7.2.3 Temperature Scale Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
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7.3 Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.3.1 Scan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.3.2 Scan Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.4 Temperature Display Hold . . . . . . . . . . . . . . . . . . . . . 25
7.4.1 Hold Temperature Display . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4.2 Mode Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4.3 Switch Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4.4 Switch Test Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7.5 Secondary Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7.6 Heater Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7.7 Proportional Band . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.8 Controller Configuration . . . . . . . . . . . . . . . . . . . . . . 28
7.9 Calibration Parameters . . . . . . . . . . . . . . . . . . . . . . . 28
7.9.1 R0. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.9.2 ALPHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.9.3 DELTA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.10 Operating Parameters . . . . . . . . . . . . . . . . . . . . . . . . 29
7.11 Serial Interface Parameters . . . . . . . . . . . . . . . . . . . . . 30
7.11.1 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.11.2 Sample Period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.11.3 Duplex Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.11.4 Linefeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8 Digital Communication Interface . . . . . . . . . . . . . . . . 33
8.1 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . 33
8.1.1 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.1.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.1.2.1 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.1.2.2 Sample Period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.1.2.3 Duplex Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.1.2.4 Linefeed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.1.3 Serial Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.2 Interface Commands . . . . . . . . . . . . . . . . . . . . . . . . 35
9 Test Probe Calibration . . . . . . . . . . . . . . . . . . . . . . 39
9.1 Calibrating a Single Probe. . . . . . . . . . . . . . . . . . . . . . 39
9.2 Dry-well Characteristics. . . . . . . . . . . . . . . . . . . . . . . 39
9.2.1 Heating and Cooling Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.2.2 Stabilization and Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . 43
10.1 Calibration Points . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.2 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . 43
10.2.1 Compute DELTA: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.2.2 Compute R
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& ALPHA: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
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10.2.3 Accuracy & Repeatability. . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
11 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
12 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . 49
12.1 Troubleshooting Problems, Possible Causes, and Solutions . . . . 49
12.2 CE Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
12.2.1 EMC Directive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
12.2.2 Low Voltage Directive (Safety) . . . . . . . . . . . . . . . . . . . . . . . . . 51
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Figures and Tables
Table 1 International Electrical Symbols . . . . . . . . . . . . . . . . . . . . . 1
Figure 1 Heat shield installed on 9141calibrator . . . . . . . . . . . . . . . . . . 5
Figure 2 9141 Back Panel and Bottom . . . . . . . . . . . . . . . . . . . . . . 15
Figure 3 9141 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 4 Inserts available for the 9141 block assembly . . . . . . . . . . . . . . 17
Figure 5 Controller Operation Flowchart . . . . . . . . . . . . . . . . . . . . . 22
Figure 6 Serial Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 2 9141 controller communications commands . . . . . . . . . . . . . . . 36
Table 2 9141 communication commands continued . . . . . . . . . . . . . . . 37
Figure 7 Typical Heating Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 8 Typical Cooling Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . 41
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1 Before You Start
1.1 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.
Tabl e 1 International Electrical Symbols
Symbol Description
AC (Alternating Current)
AC-DC
Battery
CE Complies with European Union Directives
1 Before You Start
Symbols Used
DC
Double Insulated
Electric Shock
Fuse
PE Ground
Hot Surface (Burn Hazard)
Read the User’s Manual (Important Information)
Off
On
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9141 Dry-well Calibrator
User’s Guide
Symbol Description
Canadian Standards Association
OVERVOLTAGE (Installation) CATEGORY II, Pollution Degree 2 per IEC1010-1 re
fers to the level of Impulse Withstand Voltage protection provided. Equipment of
OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from
the fixed installation. Examples include household, office, and laboratory appliances.
C-TIC Australian EMC Mark
The European Waste Electrical and Electronic Equipment (WEEE) Directive
(2002/96/EC) mark.
1.2 Safety Information
Use this instrument only as specified in this manual. Otherwise, the protection
provided by the instrument may be impaired.
The following definitions apply to the terms “Warning” and “Caution”.
• “Warning” identifies conditions and actions that may pose hazards to the
user.
• “Caution” identifies conditions and actions that may damage the instru-
ment being used.
1.2.1
WARNINGS
To avoid personal injury, follow these guidelines.
GENERAL
•
DO NOT use this instrument in environments other than those listed in
the User’s Guide.
•
Inspect the instrument for damage before each use. DO NOT use the in
strument if it appears damaged or operates abnormally.
•
Follow all safety guidelines listed in the user’s manual.
•
Calibration Equipment should only be used by Trained Personnel.
•
If this equipment is used in a manner not specified by the manufacturer,
the protection provided by the equipment may be impaired.
•
Before initial use, or after transport, or after storage in humid or semi-hu
mid environments, or anytime the dry-well has not been energized for
more than 10 days, the instrument needs to be energized for a "dry-out"
period of 2 hours before it can be assumed to meet all of the safety re
quirements of the IEC 1010-1. If the product is wet or has been in a wet
environment, take necessary measures to remove moisture prior to apply
-
-
-
-
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1 Before You Start
Safety Information
ing power such as storage in a low humidity temperature chamber operat
ing at 50°C for 4 hours or more.
DO NOT use this instrument for any application other than calibration
•
work. The instrument was designed for temperature calibration. Any other
use of the instrument may cause unknown hazards to the user.
Completely unattended operation is not recommended.
•
Overhead clearance is required. DO NOT place the instrument under a
•
cabinet or other structure. Always leave enough clearance to allow for
safe and easy insertion and removal of probes.
If the instrument is used in a manner not in accordance with the equip
•
ment design, the operation of the dry-well may be impaired or safety haz
ards may arise.
This instrument is intended for indoor use only.
•
BURN HAZARDS
• DO NOT turn the instrument upside down with the inserts in place; the
inserts will fall out.
• DO NOT operate near flammable materials.
• Use of this instrument at HIGH TEMPERATURES for extended periods
of time requires caution.
• DO NOT touch the well access surface of the instrument.
• The block vent may be very hot due to the fan blowing across the heater
block of the dry-well.
• The temperature of the well access is the same as the actual display tem-
perature, e.g. if the instrument is set to 375°C and the display reads
375°C, the well is at 375°C.
•
For top loading dry-wells, the top sheet metal of the dry-well may exhibit
extreme temperatures for areas close to the well access.
•
The air over the well can reach temperatures greater that 200°C for high
temperature (400°C and higher) dry-wells. Note: Probes and inserts may
be hot and should only be inserted and removed from the instrument
when the instrument is set at temperatures less than 50°C. Use extreme
care when removing hot inserts.
•
DO NOT turn off the instrument at temperatures higher than 100°C. This
could create a hazardous situation. Select a set-point less than 100°C and
allow the instrument to cool before turning it off.
•
The high temperatures present in dry-wells designed for operation at
300°C and higher may result in fires and severe burns if safety precau
tions are not observed.
-
-
-
-
ELECTRICAL SHOCK
•
These guidelines must be followed to ensure that the safety mechanisms
in this instrument will operate properly. This instrument must be plugged
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9141 Dry-well Calibrator
User’s Guide
into a 115 VAC, 60Hz (230 VAC, 50Hz optional), AC only electric outlet.
The power cord of the instrument is equipped with a three-pronged
grounding plug for your protection against electrical shock hazards. It
must be plugged directly into a properly grounded three-prong receptacle.
The receptacle must be installed in accordance with local codes and ordi
nances. Consult a qualified electrician. DO NOT use an extension cord or
adapter plug.
If supplied with user accessible fuses, always replace the fuse with one of
•
the same rating, voltage, and type.
Always replace the power cord with an approved cord of the correct rat
•
ing and type.
HIGH VOLTAGE is used in the operation of this equipment. SEVERE
•
INJURY or DEATH may result if personnel fail to observe safety precau
tions. Before working inside the equipment, turn power off and discon
nect power cord.
-
-
-
-
1.2.2
CAUTIONS
To avoid possible damage to the instrument, follow these guidelines.
• Always operate this instrument at room temperature between 41°F and
122°F (5°C to 50°C). Allow sufficient air circulation by leaving at least 6
inches (15 cm) of clearance around the instrument.
• Component lifetime can be shortened by continuous high temperature op-
eration.
• Hart Scientific strongly recommends using the heat shield (Figure 1) pro-
vided while operating the calibrator at temperatures above 200°C. The
heat shield protects the hub on the probes from heat and reduces the risk
of the user being burned by the hub. The heat shield gets very hot and
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1 Before You Start
Safety Information
does not prevent all heat from reaching the hub. Be careful when remov
ing the heat shield or the probe from the well.
Figure 1 Heat shield installed on 9141calibrator
-
• DO NOT apply any type of voltage to the display hold terminals. Apply-
ing a voltage to the terminals may cause damage to the controller.
•
DO NOT use fluids to clean out the well. Fluids could leak into electron
ics and damage the instrument.
•
Never introduce any foreign material into the probe hole of the insert.
Fluids, etc. can leak into the instrument causing damage.
•
DO NOT change the values of the calibration constants from the factory
set values. The correct setting of these parameters is important to the
safety and proper operation of the calibrator.
•
DO NOT slam the probe sheath in to the well. This type of action can
cause a shock to the sensor and affect the calibration.
•
The instrument and any thermometer probes used with it are sensitive in
struments that can be easily damaged. Always handle these devices with
care. DO NOT allow them to be dropped, struck, stressed, or overheated.
•
The Factory Reset Sequence (see Section 12, Troubleshooting) should be
performed only by authorized personnel if no other action is successful in
correcting a malfunction. You must have a copy of the most recent Report
of Calibration to restore the calibration parameters.
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9141 Dry-well Calibrator
User’s Guide
1.3 Authorized Service Centers
Please contact one of the following authorized Service Centers to coordinate
service on your Hart product:
Fluke Corporation, Hart Scientific Division
DO NOT operate this instrument in an excessively wet, oily, dusty, or
•
dirty environment. Always keep the well and inserts clean and clear of
foreign material.
The dry-well is a precision instrument. Although it has been designed for
•
optimum durability and trouble free operation, it must be handled with
care. Always carry the instrument in an upright position to prevent the
probe sleeves from dropping out. The convenient handle allows for hand
carrying the instrument.
If a mains supply power fluctuation occurs, immediately turn off the in
•
strument. Power bumps from brown-outs could damage the instrument.
Wait until the power has stabilized before re-energizing the instrument.
Allow for probe expansion inside the well as the block heats.
•
Most probes have handle temperature limits. Be sure that the probe handle
•
temperature limit is not exceeded in the air above the instrument.
799 E. Utah Valley Drive
American Fork, UT 84003-9775
USA
-
Phone: +1.801.763.1600
Telefax: +1.801.763.1010
E-mail: support@hartscientific.com
Fluke Nederland B.V.
Customer Support Services
Science Park Eindhoven 5108
5692 EC Son
NETHERLANDS
Phone: +31-402-675300
Telefax: +31-402-675321
E-mail: ServiceDesk@fluke.nl
Fluke Int'l Corporation
Service Center - Instrimpex
6
Page 13
Room 2301 Sciteck Tower
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
1 Before You Start
Authorized Service Centers
Phone: +65 6799-5588
Telefax: +65 6799-5588
E-mail: antng@singa.fluke.com
When contacting these Service Centers for support, please have the following
information available:
•
Model Number
•
Serial Number
•
Voltage
•
Complete description of the problem
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Page 14
2 Introduction
The Hart Scientific 9141 High-Temp Field Calibrator may be used as a portable
instrument or bench top temperature calibrator for calibrating thermocouple
and RTD temperature probes. The 9141 is small enough to use in the field, and
accurate enough to use in the lab. Calibrations may be done over a range of
50°C to 650°C (122°F to 1202°F). Temperature display of the 9141 is 0.1
degrees.
The dry-well calibrator features:
Rapid heating and cooling
•
Interchangeable multiple hole probe sleeves
•
Convenient handle
•
RS-232 interface
•
Switchable AC Input (115 VAC or 230 VAC)
•
Built in programmable features include:
• Temperature scan rate control
• Temperature switch hold
• Eight Setpoint memory
• Adjustable readout in °C or °F
The temperature is accurately controlled by Hart’s hybrid analog/digital controller. The controller uses a precision platinum RTD as a sensor and controls
the well temperature with a solid state relay (triac) driven heater.
The LED front panel continuously shows the current well temperature. The
temperature may be easily set with the control buttons to any desired tempera
ture within the specified range. The calibrator’s multiple fault protection de
vices insure user and instrument safety and protection.
The 9141 dry-well calibrator was designed for portability, low cost, and ease of
operation. Through proper use, the instrument will provide continued accurate
calibration of temperature sensors and devices. The user should be familiar
with the safety guidelines and operating procedures of the calibrator as de
scribed in the instruction manual.
2 Introduction
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3 Specifications and Environmental Conditions
3 Specifications and Environmental
Conditions
3.1 Specifications
Specifications
Power
Ambient Temperature
Operating Range
Resolution
Readout
Accuracy
Stability
Uniformity
Controller
Heater
Heating Times
Cooling Times
Stabilization Time
Immersion Depth
Cooling
Fault Protection
Test Wells
Size
Weight
115 VAC (±10%), 50–60 Hz, 1000 Watts and 230 VAC (±10%), 50–60 Hz,
switchable
5–50°C(41–121°F)
50–650°C (122–1202°F)
0.1°C or °F resolution
Switchable °C or °F
±
0.5°C up to 400°C, ±1°C 400°C to 650°C, ±2°C for holes greater than 6.5
mm (0.25")
±
0.05°C at 100°C,±0.12°C at 500°C, ±0.12°C at 650°C
±0.1°C below 400°C
±0.5°C with similar sized wells above 400°C
Hybrid analog/digital controller with data retention
1000 W
12 minutes from ambient to 650°C
25 minutes from 650°C to 100°C
7 minutes
124 mm (4.875”)
2 speed internal fan
Sensor burnout and short protection, over temperature thermal cutout
1.125" dia. x 4.87" deep. Multi-hole inserts are available.
236 mm H x 109 mm W x 185 mm D (9.3" x 4..3" x 7.3")
3.6kg(8lbs.)
3.2 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.
The instrument operates safely under the following conditions:
•
temperature range: 5 - 50°C (41 - 122°F)
•
ambient relative humidity: maximum 80% for temperature <31°C, de
-
creasing linearly to 50% at 40°C
•
pressure: 75kPa - 106kPa
•
mains voltage within ± 10% of nominal
•
vibrations in the calibration environment should be minimized
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9141 Dry-well Calibrator
User’s Guide
3.3 Warranty
Fluke Corporation, Hart Scientific Division (Hart) warrants this product to be
free from defects in material and workmanship under normal use and service
for a period as stated in our current product catalog from the date of shipment.
This warranty extends only to the original purchaser and shall not apply to any
product which, in Hart’s sole opinion, has been subject to misuse, alteration,
abuse or abnormal conditions of operation or handling.
Software is warranted to operate in accordance with its programmed instruc
tions on appropriate Hart products. It is not warranted to be error free.
Hart’s obligation under this warranty is limited to repair or replacement of a
product which is returned to Hart within the warranty period and is determined,
upon examination by Hart, to be defective. If Hart determines that the defect or
malfunction has been caused by misuse, alteration, abuse or abnormal condi
tions or operation or handling, Hart will repair the product and bill the purchaser for the reasonable cost of repair.
To exercise this warranty, the purchaser must forward the product after calling
or writing a Hart Scientific Authorized Service Center (see Section 1.3) for authorization. The Service Centers assume NO risk for in-transit damage.
THE FOREGOING WARRANTY IS PURCHASER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
IMPLIED WARRANTY OR MERCHANTABILITY, OR FITNESS FOR ANY
PARTICULAR PURPOSE OR USE. HART SHALL NOT BE LIABLE FOR
ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR LOSS WHETHER IN CONTRACT, TORT, OR OTHERWISE.
altitude does not effect the performance or safety of the unit
•
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Page 17
4 Quick Start
4.1 Unpacking
4 Quick Start
Unpacking
Unpack the dry-well carefully and inspect it for any damage that may have oc
curred during shipment. If there is shipping damage, notify the carrier
immediately.
Verify that the following components are present:
9141 Dry-well
•
3141-2, Insert A
•
Power Cord
•
Manual
•
Report of Calibration
•
Calibration Label
•
• Heat Shield
• 9930
• RS-232 Cable
• Insert Removal Tool
4.2 Set-Up
Place the calibrator on a flat surface with at least 6 inches of free space around
and 18 inches above the instrument. Plug the power cord into a grounded mains
outlet. Observe that the nominal voltage corresponds to that indicated on the
back of the calibrator. Place the heat shield on the unit to deflect high tempera
tures from the probe hubs (see Figure 1 on page 5).
-
-
CAUTION: The heat shield may become very hot. Use extreme caution.
Carefully insert the probe sleeve into the well. (DO NOT drop the sleeve in the
well.) Probe sleeve holes should be of the smallest diameter possible while still
allowing the probe to slide in and out easily. Sleeves with various hole sizes are
available from Hart Scientific. The well must be clear of any foreign objects,
dirt and grit before the sleeve is inserted. The sleeve is inserted with the two
small tong holes positioned upward.
Turn on the power to the calibrator by toggling the switch on the power entry
module. The fan should begin quietly blowing air through the instrument and
the controller display should illuminate after 3 seconds. After a brief self test
the controller should begin normal operation. If the unit fails to operate please
check the power connection.
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9141 Dry-well Calibrator
User’s Guide
The display will begin to show the well temperature and the well heater will
start operating to bring the temperature of the well to the set-point temperature.
4.3 Power
Plug the dry-well power cord into a mains outlet of the proper voltage, fre
quency, and current capability. Typically this will be 115 VAC (±10%), 50/60
Hz (230 VAC (±10%), 50/60 Hz). Turn the dry-well on using the rear panel
“POWER” switch. The dry-well will turn on and begin to heat to the previously
programmed temperature set-point. The front panel LED display will indicate
the actual dry-well temperature.
4.4 Setting the Temperature
Section 7.2 explains in detail how to set the temperature set-point on the cali
brator using the front panel keys. The procedure is summarized here.
(1) Press “SET” twice to access the set-point value.
(2) Press “UP” or “DOWN” to change the set-point value.
(3) Press “SET” to store the new set-point.
(4) Press “EXIT” to return to the temperature display.
When the set-point temperature is changed the controller will switch the well
heater on or off to raise or lower the temperature. The displayed well temperature will gradually change until it reaches the set-point temperature. The well
may require 5 to 10 minutes to reach the set-point depending on the span. Another 5 to 10 minutes is required to stabilize within ±0.1°C of the set-point. Ultimate stability may take 15 to 20 minutes more of stabilization time.
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5 Parts and Controls
The user should become familiar with the dry-well calibrator and its parts.
5.1 Bottom Panel
Figure 2 on page 15.
Power Cord - Underneath the calibrator is the removable power cord inlet that
plugs into an IEC grounded socket.
Power Switch - The power switch is located on the power entry module
(PEM). The PEM also houses the fuses and the dual voltage selector. The PEM
and Heater Voltage Switch (see below) allow the unit to be field switchable for
115 VAC (±10%) or 230 VAC (±10%) operation.
5 Parts and Controls
Bottom Panel
Figure 2 9141 Back Panel and Bottom
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9141 Dry-well Calibrator
User’s Guide
Heater Voltage Switch - To be used only when changing the input voltage.
(See Section 6.2 for instructions on changing the input voltage.)
5.2
NOTE: The input voltage and heater voltage switch settings should al
ways be the same value.
Serial Port - A DB-9 male connector is present for interfacing the calibrator to
a computer or terminal with serial RS-232 communications.
Fan - The fan inside the calibrator runs continuously when the unit is being op
erated to provide cooling for the instrument. It has two speeds, a slow speed for
control operation and a faster speed for rapid cooling. Slots at the top and
around the two corners of the calibrator are provided for airflow. The area
around the calibrator must be kept clear to allow adequate ventilation. The air
flow is directed upward and can be extremely hot.
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Figure 3 9141 Front Panel
Front Panel
Figure 3 on page 16.
Controller Display - The digital display is an important part of the temperature
controller because it not only displays set and actual temperatures but also vari
ous calibrator functions, settings, and constants. The display shows tempera
tures in units according to the selected scale °C or °F.
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Constant Temperature Block Assembly
5 Parts and Controls
Controller Keypad - The four button keypad allows easy setting of the
set-point temperature. The control buttons (SET, DOWN, UP, and EXIT) are
used to set the calibrator temperature set-point, access and set other operating
parameters, and access and set calibration parameters.
Setting the control temperature is done directly in degrees of the current scale.
It can be set to one-tenth of a degree Celsius or Fahrenheit.
The functions of the buttons are as follows:
SET – Used to display the next parameter in the menu and to store parameters
to the displayed value.
DOWN – Used to decrement the displayed value of parameters.
UP–Usedtoincrementthedisplayedvalue.
EXIT – Used to exit a function and skip to the next function. Any changes
made to the displayed value are ignored.
5.3 Constant Temperature Block Assembly
Figure 4 on page 17.
5.3.1 Constant Temperature Block
The “Block” is made of aluminum-bronze and provides a relatively constant
and accurate temperature environment for the sensor that is to be calibrated. A
28.6 mm (1.125-inch) diameter well is provided that may be used for sensors of
that size or may be sleeved down with various sized multi-hole probe sleeves.
Heaters surround the block assembly and provide even heat to the sensor. A
high-temperature platinum RTD is imbedded at the base of the block assembly
to sense and control the temperature of the block. The entire assembly is sus
pended in an air cooled chamber thermally isolated from the chassis and
electronics.
-
Interchangeable Insert Options
Insert “A”
1/16"
1/2"
1/8"
Figure 4 Inserts available for the 9141 block assembly
1/4"
3/16"
3/8"
3/8"
3/16"
1/4"
Insert “B”
1/4"
3/16"
3/8"
1/4"
Insert “C”
6mm
3mm
4mm
Insert “D”
4mm
6mm
3mm
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9141 Dry-well Calibrator
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CAUTION: The block vent cover may be very hot due to the fan blowing
upward. Please use caution.
5.3.2 Probe Sleeves and Tongs
The calibrator is supplied with a multi-hole aluminum-bronze probe sleeve for
insertion into the calibrator well and tongs for removing sleeves. Probe sleeves
of various hole sizes are available to allow the user’s probe to fit snugly into the
well whatever the diameter of the probe.
One insert, whichever is ordered, is shipped with the unit:
or
Insert A (variety block): 1/2", 3/8",3/16"”,1/8", and 1/16"holes
•
Insert B (comparison block): two 3/8", two 1/4", and two 3/16" holes
•
Insert C (1/4” comparison block): six 1/4" holes
•
Insert D (metric block): two 3 mm, two 4 mm, and two 6 mm holes
•
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6 General Operation
6.1 Changing Display Units
The 9141 can display temperature in Celsius or Fahrenheit. The temperature
units are shipped from the factory set to Celsius. To change to Fahrenheit or
back to Celsius there are two ways:
1 - Press the “SET” and “UP” simultaneously. This will change display units.
2 - Press the “SET” key three times from the temperature display to show
Un= C
Press the “UP” or “Down” key to change units.
Press “SET” to store changes.
6.2 Switching to 230V Operation
The 9141 is switchable from 115 VAC to 230 VAC 50/60 Hz. Switching the
voltage can change the calibration, so the unit should be calibrated after
changing the input voltage.
To change from 115 VAC to 230 VAC:
6 General Operation
Changing Display Units
• Unplug the unit.
• Lay the unit down on its side.
• With a small straight slot screwdriver remove the fuse holder located on
the rear panel. Replace the two fuses (10 amp 250 V) with 5 amp 250V
fuses.
•
Replace the fuse holder with the “230V” in the display window.
•
Using the same straight slot screwdriver, move the heater switch to dis
play “230V”. See the rear panel drawing in Figure 2 on page 15.
NOTE: If the heater switch and the fuse holder do not both read 230V when
complete, the unit will either not heator only heat at a fraction of its capacity.
If not done properly, the unit could become damaged and void the calibration
and warranty. Use 10 amp fuses for 115V and 5 amp for 230V only. DO NOT
PLUG THE UNIT INTO 230 V IF THE HEATER SWITCH AND FUSE
HOLDER READ 115. THIS WILL CAUSE THE FUSES TO BLOW AND
MAY DAMAGE THE INSTRUMENT.
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7 Controller Operation
7 Controller Operation
Well Temperature
This chapter discusses in detail how to operate the dry-well temperature con
troller using the front control panel. Using the front panel key-switches and
LED display the user may monitor the well temperature, set the temperature
set-point in degrees C or F, monitor the heater output power, adjust the control
ler proportional band, and program the calibration parameters, operating pa
rameters, and serial interface configuration. Operation of the functions and
parameters are shown in the flowchart in Figure 5 on page 22. This chart may
be copied for reference.
In the following discussion a button with the word SET, UP, EXIT or DOWN
inside indicates the panel button while the dotted box indicates the display
reading. Explanation of the button or display reading are to the right of each
button or display value.
7.1 Well Temperature
The digital LED display on the front panel allows direct viewing of the actual
well temperature. This temperature value is what is normally shown on the display. The units, C or F, of the temperature value are displayed at the right. For
example,
100.0 C
The temperature display function may be accessed from any other function by
pressing the “EXIT” button.
Well temperature in degrees Celsius
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7.2 Temperature Set-point
The temperature set-point can be set to any value within the range and resolu
tion as given in the specifications. Be careful not to exceed the safe upper tem
perature limit of any device inserted into the well.
Setting the temperature involves two steps: (1) select the set-point memory and
(2) adjust the set-point value.
7.2.1 Programmable Set-points
The controller stores 8 set-point temperatures in memory. The set-points can be
quickly recalled to conveniently set the calibrator to a previously programmed
temperature set-point.
To set the temperature one must first select the set-point memory. This function
is accessed from the temperature display function by pressing “SET”. The
number of the set-point memory currently being used is shown at the left on the
display followed by the current set-point value.
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9141 Dry-well Calibrator
User’s Guide
Figure 5 Controller Operation Flowchart
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7 Controller Operation
Temperature Set-point
100.0 C
S
Access set-point memory
1. 100.
To change to another set-point memory press “UP” or “DOWN”.
4. 300.
Press “SET” to accept the new selection and access the set-point value.
S
Accept selected set-point memory
7.2.2 Set-point Value
The set-point value may be adjusted after selecting the set-point memory and
pressing “SET”.
4 200.
If the set-point value is correct then press “EXIT” to resume displaying the well
temperature. To change the set-point values, press “SET” and then press “UP”
or “DOWN” to adjust the set-point value.
Well temperature in degrees Celsius
Set-point memory 1, 100°C currently used
New set-point memory 4, 300°C
Set-point 4 value in°C
220.
When the desired set-point value is reached press “SET” to accept the new
value and access the temperature scale units selection. If “EXIT” is pressed in
stead then any changes made to the set-point will be ignored.
S
Accept new set-point value
New set-point value
7.2.3 Temperature Scale Units
The temperature scale units of the controller maybe set by the user to degrees
Celsius (°C) or Fahrenheit (°F). The units are used in displaying the well tem
perature, set-point, and proportional band.
Press “SET” after adjusting the set-point value to change display units.
Un= C Scale units currently selected
Press “UP” or “DOWN” to change the units.
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9141 Dry-well Calibrator
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7.3 Scan
The scan rate can be set and enabled so that when the set-point is changed the
dry-well heats or cools at a specified rate (degrees per minute) until it reaches
the new set-point. With the scan disabled the dry-well heats or cools at the
maximum possible rate.
7.3.1 Scan Control
The scan is controlled with the scan on/off function that appears in the main
menu after the temperature scale units.
Un= F New units selected
Sc=OFF
Press “UP” or “DOWN” to toggle the scan on or off.
Sc=On
Press “SET” to accept the present setting and continue.
S
Accept scan setting
7.3.2 Scan Rate
The next function in the main menu is the scan rate. The scan rate can be set
from .1 to 99.9°C/min. The maximum scan rate however is actually limited by
the natural heating or cooling rate of the instrument. This is often less than
100°C/min, especially when cooling.
The scan rate function appears in the main menu after the scan control function.
The scan rate units are in degrees per minute, degrees C or F depending on the
selected units.
Sr= 10.0
Press“UP”or“DOWN”tochangethescanrate.
Sr= 2.0
Scan function off
Scan function on
Scan rate in°C/min
New scan rate
24
Press “SET” to accept the new scan rate and continue.
S
Accept scan rate
Page 28
7.4 Temperature Display Hold
The 9141 has a display hold function which allows action of an external switch
to freeze the displayed temperature and stop the set-point from scanning. This
is useful for testing thermal switches and cutouts. This section explains the
functions available for operating the temperature hold feature. An example fol
lows showing how to set up and use the hold feature to test a switch.
7.4.1 Hold Temperature Display
The hold feature is enabled by simply pressing the “UP” button. The hold tem
perature display shows the hold temperature on the right and the switch status
on the left. For the status “c” means the switch is closed and “o” means the
switch is open. The status flashes when the switch is in its active position (op
posite the normal position). The hold temperature shows what the temperature
of the well was when the switch changed from its normal position to its active
position. While the switch is in the normal position the hold temperature will
follow the well temperature. Operation of the hold temperature display is out
lined below.
7 Controller Operation
Temperature Display Hold
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143.5 C
U
Access hold display
c 144.8
To return to the normal well temperature display press “DOWN”.
7.4.2 Mode Setting
The Hold Function is always in the automatic mode. In this mode the normal
position is set to whatever the switch position is when the set-point is changed.
For example, if the switch is currently open when the set-point is changed, the
closed position then becomes the new active position. The normal position is
set automatically under any of the following conditions, (1) a new set-point
number is selected, (2) the set-point value is changed, (3) a new set-point is set
through the communications channels.
The operating mode of the temperature hold is set in the primary menu after the
scan rate setting.
7.4.3 Switch Wiring
The thermal switch or cutout is wired to the calibrator at the two terminals in
the front of the dry-well calibrator labeled “SWITCH HOLD”. The switch
wires may be connected to the terminals either way. Internally the black termi
nal connects to ground. The red terminal connects to +5V through a 100 kΩ re
Well temperature display
Switch status and hold temperature
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9141 Dry-well Calibrator
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sistor. The calibrator measures the voltage at the red terminal and interprets
+5V as open and 0V as closed.
7.4.4 Switch Test Example
This section describes a possible application for the temperature hold feature
and how the instrument is set up and operated.
Suppose you have a thermal switch which is supposed to open at about 75°C
and close at about 50°C and you want to test the switch to see how accurate and
repeatable it is. You can use the temperature hold feature and the scan function
to test the switch. Measurements can be made by observing the display or, pref
erably, by collecting data using a computer connected to the RS-232 port. To
set up the test do the following steps.
1. Connect the switch wires to the terminals on the front of the dry-well and
place the switch in the well.
2. Enable set-point scanning by setting the scan to “ON” in the primary menu
(see Section 7.3.1).
3. Set the scan rate to a low value, say 1.0°C/min. (see Section 7.3.2). If the
scan rate is too high you may lose accuracy because of transient temperature
gradients. If the scan rate is too low the duration of the test may be longer than
is necessary. You may need to experiment to find the best scan rate.
4. Set the first program set-point to a value below the expected lower switch
temperature, say 40°C, in the program menu.
5. Set the second program set-point to a value above the expected upper switch
temperature, say 90°C.
6. Set the program soak time to allow enough time to collect a number of data
points, say 2 minutes.
7. Collect data on a computer connected to the RS-232 port. Refer to Section 8
for instructions on configuring the RS-232 communications interface.
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26
7.5 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. The first function in the secondary menu is the
heater power display. (See Figure 5 on page 22.)
7.6 Heater Power
The temperature controller controls the temperature of the well by pulsing the
heater on and off. The total power being applied to the heater is determined by
the duty cycle or the ratio of heater on time to the pulse cycle time. By knowing
the amount of heating the user can tell if the calibrator is heating up to the
set-point, cooling down, or controlling at a constant temperature. Monitoring
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7 Controller Operation
Proportional Band
the percent heater power will let the user know how stable the well temperature
is. With good control stability the percent heating power should not fluctuate
more than ±1% within one minute.
The heater power display is accessed in the secondary menu. Press “SET” and
“EXIT” simultaneously and release. The heater power will be displayed as a
percentage of full power.
100.0 C
S+E
Well temperature
Access heater power in secondary menu
SEC Flashes for secondary menu and then displays the
heater power
12.0 P
To exit out of the secondary menu press “EXIT”. To continue on to the proportional band setting function press “SET”.
Heater power in percent
7.7 Proportional Band
In a proportional controller such as this the heater output power is proportional
to the well temperature over a limited range of temperatures around the
set-point. This range of temperature is called the proportional band. At the bottom of the proportional band the heater output is 100%. At the top of the proportional band the heater output is 0. Thus as the temperature rises the heater
power is reduced, which consequently tends to lower the temperature back
down. In this way the temperature is maintained at a fairly constant
temperature.
The temperature stability of the well and response time depend on the width of
the proportional band. If the band is too wide the well temperature will deviate
excessively from the set-point due to varying external conditions. This is be
cause the power output changes very little with temperature and the controller
cannot respond very well to changing conditions or noise in the system. If the
proportional band is too narrow the temperature may swing back and forth be
cause the controller overreacts to temperature variations. For best control stabil
ity the proportional band must be set for the optimum width.
The proportional band width is set at the factory to about 15.0°C. The propor
tional band width may be altered by the user if he desires to optimize the con
trol characteristics for a particular application.
The proportional band width is easily adjusted from the front panel. The width
may be set to discrete values in degrees C or F depending on the selected units.
The proportional band adjustment is be accessed within the secondary menu.
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9141 Dry-well Calibrator
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Press “SET” and “EXIT” to enter the secondary menu and show the heater
power. Then press “SET” to access the proportional band.
S+E
Access heater power in secondary menu
SEC Flashes for secondary menu and then displays the
heater power
Heater power in percent
Proportional band setting
S
12.0 P
Access proportional band
4.1
ProP Flashes and then displays the value
To change the proportional band press “UP” or “DOWN”.
10.0
To accept the new setting press “SET”. Press “EXIT” to continue without storing the new value.
S
Accept the new proportional band setting
New proportional band setting
28
7.8 Controller Configuration
The controller has a number of configuration and operating options and calibra
tion parameters which are programmable via the front panel. These are ac
cessed from the secondary menu after the proportional band function by
pressing “SET”. Pressing “SET” again enters the first of three sets of configu
ration parameters — calibration parameters, operating parameters and serial in
terface parameters. The sets are selected using the “UP” and “DOWN” keys
andthenpressing“SET”.(SeeFigure 5 on page 22.)
7.9 Calibration Parameters
The operator of the instrument controller has access to a number of the calibra
tion constants namely R0, ALPHA, and DELTA. These values are set at the
factory and must not be altered. The correct values are important to the accu
racy and proper and safe operation of the instrument. Access to these parame
ters is available to the user so that in the event that the controller memory fails
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7 Controller Operation
Operating Parameters
the user may restore these values to the factory settings. The user should have a
list of these constants and their settings with the instrument manual.
WARNING: DO NOT change the values of the instrument calibration
constants from the factory set values. The correct setting of these parame
ters is important to the safety and proper operation of the instrument.
The calibration parameters menu is indicated by,
-
CAL
Press “SET” five times to enter the menu. The calibration parameters menu
contains the parameters, R
sistance-temperature relationship of the platinum control sensor. These parame
ters may be adjusted to improve the accuracy of the calibrator.
The calibration parameters are accessed by pressing “SET” after the name of
the parameter is displayed. The value of the parameter may be changed using
the “UP” and “DOWN” buttons. After the desired value is reached press “SET”
to set the parameter to the new value. Pressing “EXIT” causes the parameter to
be skipped ignoring any changes that may have been made.
7.9.1 R
0
This probe parameter refers to the resistance of the control probe at 0°C. The
value of this parameter is set at the factory for best instrument accuracy.
7.9.2 ALPHA
This probe parameter refers to the average sensitivity of the probe between 0
and 100°C. The value of this parameter is set at the factory for best instrument
accuracy.
7.9.3 DELTA
This probe parameter characterizes the curvature of the resistance-temperature
relationship of the sensor. The value of this parameter is set at the factory for
best instrument accuracy.
Calibration parameters menu
, ALPHA, and DELTA, which characterize the re
0
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-
7.10 Operating Parameters
The operating parameters menu is indicated by,
PAr
Press “UP” to enter the menu. The operating parameters menu contains the HL
(High Limit) parameter. The HL parameter adjusts the upper set-point tempera
Operating parameters menu
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9141 Dry-well Calibrator
User’s Guide
ture. The factory default and maximum are set to 650°C. For safety, a user can
adjust the HL down so the maximum temperature set-point is restricted.
HL
Press “SET” to enable adjustment of HL
H=650
Adjust the HL parameter using “UP” or “DOWN”.
H=400
Pres “SET” to accept the new temperature limit.
High Limit parameter
Current HL setting
New HL setting
7.11 Serial Interface Parameters
The serial RS-232 interface parameters menu is indicated by,
SErIAL
The serial interface parameters menu contains parameters which determine the
operation of the serial interface. These controls only apply to instruments fitted
with the serial interface. The parameters in the menu are — BAUD rate, sample
period, duplex mode, and linefeed.
7.11.1 Baud Rate
The baud rate is the first parameter in the menu. The baud rate setting deter
mines the serial communications transmission rate.
The baud rate parameter is indicated by,
Serial RS-232 interface parameters menu
-
30
bAUd
Press “SET” to choose to set the baud rate. The current baud rate value will
then be displayed.
2400 b
The baud rate of the serial communications may be programmed to 300, 600,
1200, 2400, 4800, or 9600 baud. Use “UP” or “DOWN” to change the baud
rate value.
4800 b
Serial BAUD rate parameter
Current baud rate
New baud rate
Page 34
7 Controller Operation
Serial Interface Parameters
Press “SET” to set the baud rate to the new value or “EXIT” to abort the opera
tion and skip to the next parameter in the menu.
7.11.2 Sample Period
The sample period is the next parameter in the serial interface parameter menu.
The sample period is the time period in seconds between temperature measure
ments transmitted from the serial interface. If the sample rate is set to 5, the in
strument transmits the current measurement over the serial interface
approximately every five seconds. The automatic sampling is disabled with a
sample period of 0. The sample period is indicated by,
SPer
Press “SET” to choose to set the sample period. The current sample period
value will be displayed. Press “EXIT” to exit without saving the changes.
SP= 1
Adjust the value with “UP” or “DOWN” and then use “SET” to set the sample
rate to the displayed value.
SP= 60
7.11.3 Duplex Mode
The next parameter is the duplex mode. The duplex mode may be set to full duplex or half duplex. With full duplex any commands received by the calibrator
via the serial interface are immediately echoed or transmitted back to the device
of origin. With half duplex the commands are executed but not echoed. The du
plex mode parameter is indicated by,
-
-
-
Serial sample period parameter
Current sample period (seconds)
New sample period
-
dUPL
Press “SET” to access the mode setting.
d=FULL
The mode may be changed using “UP” or “DOWN” and pressing “SET”.
d=HALF
7.11.4 Linefeed
The final parameter in the serial interface menu is the linefeed mode. This pa
rameter enables (on) or disables (off) transmission of a linefeed character (LF,
Serial duplex mode parameter
Current duplex mode setting
New duplex mode setting
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9141 Dry-well Calibrator
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ASCII 10) after transmission of any carriage-return. The linefeed parameter is
indicated by,
LF
Press “SET” to access the linefeed parameter.
LF= On
The mode may be changed using “UP” or “DOWN” and pressing “SET”.
LF= OFF
Serial linefeed parameter
Current linefeed setting
New linefeed setting
32
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8 Digital Communication Interface
8 Digital Communication Interface
The dry-well calibrator is capable of communicating with and being controlled
by other equipment through the digital serial interface.
With a digital interface the instrument may be connected to a computer or other
equipment. This allows the user to set the set-point temperature, monitor the
temperature, and access any of the other controller functions, all using remote
communications equipment. Communications commands are summarized in
Table 2 on page 36.
8.1 Serial Communications
Serial Communications
The calibrator is installed with an RS-232 serial interface that allows serial dig
ital communications over fairly long distances. With the serial interface the user
may access any of the functions, parameters and settings discussed in Section7
with the exception of the BAUD rate setting.
8.1.1 Wiring
The serial communications cable attaches to the calibrator
through the D-9 connector at
the back of the instrument. Figure 6 shows the pin-out of this
connector and suggested cable
wiring. The serial cable should
be shielded. If the unit is used
in a heavy industrial setting, the
serial cable must be limited to
ONE meter.
8.1.2 Setup
Before operation the serial in
terface must first be set up by
programming the BAUD rate
and other configuration param
eters. These parameters are pro
grammed within the serial
interface menu. The serial inter
face parameters menu is out
lined in Figure 5 on page 22.
To enter the serial parameter
programming mode first press
“EXIT” while pressing “SET”
and release to enter the second
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Figure 6 Serial Cable Wiring
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9141 Dry-well Calibrator
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ary menu. Press “SET” repeatedly until the display reads “CAL”. Press “UP”
until the serial interface menu is indicated with “SErIAL”. Finally press “SET”
to enter the serial parameter menu. In the serial interface parameters menu are
the BAUD rate, the sample rate, the duplex mode, and the linefeed parameter.
8.1.2.1 Baud Rate
The baud rate is the first parameter in the menu. The display will prompt with
the baud rate parameter by showing “bAUd”. Press “SET” to choose to set the
baud rate. The current baud rate value will then be displayed. The BAUD rate
of the 9141 serial communications may be programmed to 300, 600, 1200,
2400, 4800, or 9600 baud. The baud rate is pre-programmed to 2400 BAUD.
Use“UP”or“DOWN”tochangethebaudratevalue.Press“SET”tosetthe
baud rate to the new value or “EXIT” to abort the operation and skip to the next
parameter in the menu.
8.1.2.2 Sample Period
The sample period is the next parameter in the menu and prompted with
“SPEr”. The sample period is the time period in seconds between temperature
measurements transmitted from the serial interface. If the sample rate is set to 5
for instance then the instrument will transmit the current measurement over the
serial interface approximately every five seconds. The automatic sampling is
disabled with a sample period of 0. Press “SET” to choose to set the sample period. Adjust the period with “UP” or “DOWN” and then use “SET” to set the
sample rate to the displayed value.
34
8.1.2.3 Duplex Mode
The next parameter is the duplex mode indicated with “dUPL”. The duplex
mode may be set to half duplex (“HALF”) or full duplex (“FULL”). With full
duplex any commands received by the thermometer via the serial interface are
immediately echoed or transmitted back to the device of origin. With half du
plex the commands are executed but not echoed. The default setting is full du
plex. The mode may be changed using “UP” or “DOWN” and pressing “SET”.
8.1.2.4 Linefeed
The final parameter in the serial interface menu is the linefeed mode. This pa
rameter enables (“On”) or disables (“OFF”) transmission of a linefeed charac
ter (LF, ASCII 10) after transmission of any carriage-return. The default setting
is with linefeed on. The mode may be changed using “UP” or “DOWN” and
pressing “SET”.
8.1.3 Serial Operation
Once the cable has been attached and the interface set up properly the control
ler immediately begins transmitting temperature readings at the programmed
rate. The serial communications uses 8 data bits, one stop bit, and no parity.
The set-point and other commands may be sent via the serial interface to set the
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8 Digital Communication Interface
Interface Commands
temperature set-point and view or program the various parameters. The inter
face commands are discussed in Section . All commands are ASCII character
strings terminated with a carriage-return character (CR, ASCII 13).
8.2 Interface Commands
The various commands for accessing the calibrator functions via the digital in
terfaces are listed in this section (see Table 2). These commands are used with
the RS-232 serial interface. The commands are terminated with a carriage-re
turn character. The interface makes no distinction between upper and lower
case letters, hence either may be used. Commands may be abbreviated to the
minimum number of letters which determines a unique command. A command
may be used to either set a parameter or display a parameter depending on
whether or not a value is sent with the command following a “=” character. For
example “s”<CR> returns the current set-point and “s=150.0”<CR> sets the
set-point to 150.0 degrees.
In the following list of commands, characters or data within brackets, “[” and
“]”, are optional for the command. A slash, “/”, denotes alternate characters or
data. Numeric data, denoted by “n”, may be entered in decimal or exponential
notation. Characters are shown in lower case although upper case may be used.
Spaces may be added within command strings and will simply be ignored.
Backspace (BS, ASCII 8) may be used to erase the previous character. A terminating CR is implied with all commands.
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9141 Dry-well Calibrator
User’s Guide
Tabl e 2 9141 controller communications commands
Command Description
Display Temperature
Read current set-point s[etpoint] s set: 9999.99 {C or F} set: 150.00 C
Set current set-point to n s[etpoint]=n s=350 Instrument
Read temperature t[emperature] t t: 9999.9 {C or F} t: 55.6 C
Read temperature units u[nits] u u: x u: C
Set temperature units: u[nits]=c/f
Set temperature units to Celsius u[nits]=c u=c
Set temperature units to
Fahrenheit
Read scan mode sc[an] sc sc: {ON or OFF} sc: ON
Set scan mode sc[an]=on/off sc=on ON or OFF
Read scan rate sr[ate] sr srat: 99.9 {C or F}/min srat:12.4 C/min
Set scan rate sr[ate]=n sr=1.1 .1 to 99.9
Read hold ho[ld] ho ho: open/closed, 99.9 {C
Secondary Menu
Read proportional band setting pr[opband] pr pb: 999.9 pb: 15.9
Set proportional band to
Read heater power
(duty cycle)
Configuration Menu
Calibration Parameters Menu
Read R0 calibration parameter r[0] r r0: 999.999 r0: 100.578
Set R0 calibration parameter to
Read ALPHA calibration
parameter
Set ALPHA calibration parameter
to
n
Read DELTA calibration
parameter
Set DELTA calibration parameter de[lta]=n de=1.3742 0–3.0
Operating Parameters Menu
Read High Limit hl hl hl: 999 hl: 600
Set High Limit hl=
n
Command
Format
u[nits]=f u=f
pr[opband]=n pr=8.83 Depends on
po[wer] po po: 999.9 po: 1.3
n
r[0]=n r=100.324 98.0 to 104.9
al[pha] al al: 9.9999999 al: 0.0038573
al[pha]=n al=0.0038433 .002 to .006
de[lta] de de: 9.9999 de: 1.507
n
Command
Example Returned
or F}
hl=600 100–650
Returned
Example
ho: open, 30.5C
Acceptable
Values
Range
CorF
Configuration
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9141 communication commands continued
8 Digital Communication Interface
Interface Commands
Command Description
Serial Interface Menu
Read serial sample setting sa[mple] sa sa: 9 sa: 1
Set serial sampling setting to
seconds
Set serial duplex mode: du[plex]=f[ull]/h[alf]
Set serial duplex mode to full du[plex]=f[ull] du=f
Set serial duplex mode to half du[plex]=h[alf] du=h
Set serial linefeed mode: lf[eed]=on/of[f]
Set serial linefeed mode to on lf[eed]=on lf=on
Set serial linefeed mode to off lf[eed]=of[f] lf=of
Miscellaneous
Read firmware version number *ver[sion] *ver ver.9999,9.99 ver.9141,1.21
Read structure of all commands h[elp] h list of commands
Read ALL operating parameters all all list of parameters
Legend: [] Optional Command data
Note: When DUPLEX is set to FULL and a command is sent to READ, the command is returned followed by a
Command
Format
n
sa[mple]=n sa=0 0 to 999
{} Returns either information
n Numeric data supplied by user
9 Numeric data returned to user
x Character data returned to user
carriage return and linefeed. Then the value is returned as indicated in the RETURNED column.
Command
Example Returned
Returned
Example
Acceptable
Values
FULL or HALF
ON or OFF
37
Page 41
9 Test Probe Calibration
For optimum accuracy and stability, allow the calibrator to warm up for 10
minutes after power-up and then allow adequate stabilization time after reach
ing the set-point temperature. After completing operation of the calibrator, al
low the well to cool by setting the temperature to 100°C for one-half hour
before switching the power off.
9.1 Calibrating a Single Probe
Insert the probe to be calibrated into the well of the dry-well calibrator. The
probe should fit snugly into the calibrator probe sleeve yet should not be so
tight that it cannot be easily removed. Avoid any dirt or grit that may cause the
probe to jam into the sleeve. Best results are obtained with the probe inserted to
the full depth of the well. Once the probe is inserted into the well, allow ade
quate stabilization time to allow the test probe temperature to settle as de
scribed above. Once the probe has settled to the temperature of the well, it may
be compared to the calibrator display temperature. The display temperature
should be stable to within 0.1°C degree for best results.
CAUTION: Never introduce any foreign material into the probe hole of
the insert. Fluids etc. can leak into the calibrator causing damage to the
calibrator or binding and damage to your probe.
9 Test Probe Calibration
Calibrating a Single Probe
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9.2 Dry-well Characteristics
There is a temperature gradient vertically in the test well. The heater has been
applied to the block in such a way as to compensate for nominal heat losses out
of the top of the dry-well. However, actual heat losses will vary with design of
the thermometer probes inserted into the calibrator and the temperature. For
best results, insert probe to full depth of well.
9.2.1 Heating and Cooling Rates
Figures 7 and 8 show typical heating cooling rates of the 9141 dry-well
calibrator.
DO NOT remove inserts when heating or when the unit is hot.
9.2.2 Stabilization and Accuracy
The stabilization time of the dry-well calibrator will depend on the conditions
and temperatures involved. Typically the test well will be stable to 0.1°C within
5 minutes of reaching the set-point temperature as indicated by the display. Ul
timate stability will be achieved 10 to 20 minutes after reaching the set
temperature.
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9141 Dry-well Calibrator
User’s Guide
Inserting a cold probe into a well will require another period of stabilizing de
pending on the magnitude of the disturbance and the required accuracy. For ex
ample, inserting a .25 inch diameter room temperature probe into a sleeve at
300°C will take 5 minutes to be within 0.1°C of its settled point and will take
10 minutes to achieve maximum stability.
Speeding up the calibration process can be accomplished by knowing how soon
to make the measurement. It is recommended that typical measurements be
made at the desired temperatures with the desired test probes to establish these
times.
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Page 43
600
500
400
300
200
Block Temperature °C
100
Ambient
9 Test Probe Calibration
Dry-well Characteristics
24
Figure 7 Typical Heating Rate
650
540
430
320
210
Block Temperature °C
100
Ambient
48
6810
Time in Minutes
12 16 20
Time in Minutes
12
24
Figure 8 Typical Cooling Rate
41
Page 44
10 Calibration Procedure
10 Calibration Procedure
Calibration Points
Sometimes the user may want to calibrate the dry-well to improve the tempera
ture set-point accuracy. Calibration is done by adjusting the controller probe
calibration constants R
, ALPHA,andD ELTA so that the temperature of the
0
dry-well as measured with a standard thermometer agrees more closely with the
set-point. The thermometer used must be able to measure the well temperature
with higher accuracy than the desired accuracy of the dry-well. By using a
good thermometer and following this procedure the dry-well can be calibrated
to an accuracy of better than 0.5°C up to 450°C and 1.5°C above 450°C.
10.1 Calibration Points
In calibrating the dry-well, R0, ALPHA,andD ELTA are adjusted to minimize
the set-point error at each of three different dry-well temperatures. Any three
reasonably separated temperatures may be used for the calibration. Improved
results can be obtained for shorter ranges when using temperatures that are just
within the most useful operating range of the dry-well. The farther apart the
calibration temperatures, the larger will be the calibrated temperature range but
the calibration error will also be greater over the range. If for instance 150°C to
350°C is chosen as the calibration range then the calibrator may achieve an ac-
curacy of say ±0.3°C over the range 150 to 350°C. Choosing a range of 200°C
to 300°C may allow the calibrator to have a better accuracy of maybe ±0.2°C
over the range 175 to 325°C but outside that range the accuracy may be only
±0.5°C.
10.2 Calibration Procedure
-
1. Choose three set-points to use in the calibration of the R0,ALPHA,and
DELTA parameters. These set-points are generally 50°C, 250°C, and 450°C but
other set-points may be used if desired or necessary.
2. Set the dry-well to the low set-point. When the dry-well reaches the set-point
and the display is stable, wait 15 minutes or so and then take a reading from the
thermometer. Sample the set-point resistance by holding down the SET key and
pressing the DOWN key. Write these values down as T
3. Repeat step 2 for the other two set-points recording them as T
R
respectively.
3
4. Using the recorded data, calculate new values for R
parameters using the equations given below:
10.2.1 Compute DELTA:
ATT=−
32
BTT=−
21
and R1respectively.
1
2,R2,T3
, ALPHA, and DELTA
0
,and
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9141 Dry-well Calibrator
User’s Guide
C
T
1-3
R
1-3
time.)
where
T
1
T
2
T
3
TTTT
⎡
⎤
⎡
⎤
⎡
⎤
⎡
3322
=
⎢
⎣
⎡
D
=
⎢
⎣
ERR=−
FRR=−
delta
−
⎥
⎢
1001100 1001100
⎦
⎣
TTTT
⎤
⎡
2211
⎥
⎢
1001100 1001100
⎦
⎣
32
21
AF BE
=
DE CF
−
⎥
⎢
⎦
⎣
⎤
−
⎡
−
⎥
⎢
⎦
⎣
−
−
⎥
⎦
⎤
⎥
⎦
⎤
−
⎥
⎢
⎣
⎦
⎡
⎤
−
⎥
⎢
⎣
⎦
- Measured temperature using thermometer.
- Value of R from display of 9141 (Press SET and DOWN at the same
and R1are the measured temperature and resistance at 50.0 °C
and R2are the measured temperature and resistance at 250.0 °C
and R3are the measured temperature and resistance at 450.0 °C
44
10.2.2 Compute R0& ALPHA:
TT
⎡
⎤
⎡
=+
a T delta
11
=+
a T delta
33
Ra Ra
rzero
alpha
31 13
=
=
Ra Ra
11
⎢
1001100
⎣
TT
⎡
33
⎢
1001100
⎣
−
aa
−
13
RR
−
13
−
31 13
⎥
⎦
⎤
⎥
⎦
delta is the new value of DELTA computed above
5. Program the new values for DELTA (delta), R
into the dry-well with the following steps.
a. Press SET and EXIT keys at the same time and then press SET until R
is displayed.
⎤
−
⎢
⎥
⎣
⎦
⎡
⎤
−
⎢
⎥
⎣
⎦
(rzero) and ALPHA (alpha)
0
0
Page 46
b. Press SET then use the UP or DOWN keys until the correct numerical
setting is displayed. Press SET to accept the new value.
c. Repeat step b for ALPHA and DELTA.
10.2.3 Accuracy & Repeatability
1. Check the accuracy of the dry-well at various points over the calibrated
range.
10 Calibration Procedure
Calibration Procedure
2. If dry-well does not pass specification at all set-points, repeat the Calibra
tion Procedure.
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11 Maintenance
The calibration instrument has been designed with the utmost care. Ease
•
of operation 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
an oily, wet, dirty, or dusty environment.
If the outside of the instrument becomes soiled, it may be wiped clean
•
with a damp cloth and mild detergent. Do not use harsh chemicals on the
surface which may damage the paint.
It is important to keep the well of the calibrator clean and clear of any for
•
eign matter. Do not use fluid to clean out the well.
The dry-well calibrator should be handled with care. Avoid knocking or
•
dropping the calibrator.
For dry-wells with removable probe sleeves, the sleeves can become cov
•
ered with dust and carbon material. If the buildup becomes too thick, it
could cause the sleeves to become jammed in the wells. Avoid this build
up by periodically buffing the sleeves clean.
• If a sleeve should be dropped, examine the sleeve for deformities before
inserting it in the well. If there is any chance of jamming the sleeve in the
well, file or grind off the protuberance.
• Do not slam the probe stems into the well. This type of action can cause a
shock to the sensor.
• 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.
•
If the mains supply cord becomes damaged, replace it with a cord with
the appropriate gauge wire for the current of the instrument. If there are
any questions, call a Hart Scientific Authorized Service Center for more
information.
•
Before using any cleaning or decontamination method except those rec
ommended by Hart, users should check with a Hart Scientific Authorized
Service Center to be sure that the proposed method will not damage the
equipment.
•
If the instrument is used in a manner not in accordance with the equip
ment design, the operation of the dry-well may be impaired or safety haz
ards may arise.
11 Maintenance
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12 Troubleshooting
12 Troubleshooting
This section contains information on troubleshooting, CE Comments, and a
wiring diagram.
12.1 Troubleshooting Problems, Possible Causes,
and Solutions
In the event that the instrument appears to function abnormally, this section
may help to find and solve the problem. Several possible problem conditions
are described along with likely causes and solutions. If a problem arises, please
read this section carefully and attempt to understand and solve the problem. If
the problem cannot otherwise be solved, contact a Hart Scientific Authorized
Service Center (see Section 1.3) for assistance. Be sure to have the instru
ment’s model number, serial number, voltage, and problem description
available.
Problem Possible Causes and Solutions
Incorrect temperature reading
Incorrect R0, ALPHA, DELTA, or BETA parameters. Find the value for R0, ALPHA, DELTA, and BETA on the Report of Calibration. Reprogram the parameters
into the instrument (see Section 7.9, Calibration Parameters). Allow the instrument
to stabilize and verify the accuracy of the temperature reading.
-
The instrument
heats or cools too
quickly or too slowly
An “o” is displayed
at the left of the
display
Controller locked up. The controller may have locked up due to a power surge or
other aberration. Initialize the system by performing the Factory Reset Sequence.
Factory Reset Sequence. Hold “SET” and “EXIT” down at the same time while
turning on the instrument. The instrument displays shows ‘-init-‘, the model number,
and the firmware version (release “SET” and “EXIT”). Each of the controller param
eters and calibration constants must be reprogrammed. The values can be found
on the Report of Calibration.
Incorrect scan and scan rate settings. The scan and scan rate settings may be
set to unwanted values. Check the Scan and Scan Rate settings. The scan may be
off (if the unit seems to be responding too quickly). The scan may be on with the
Scan Rate set low (if unit seems to be responding too slowly).
Improper line voltage. Verify that the voltage reading in the bottom of the unit
matches the source voltage.
Improper switch setting. Check the 115 VAC/230 VAC switch on the PEM (power
entry module). Make sure this switch is set to the correct type of input voltage.
Check the 115 VAC/230 VAC heater switch. Make sure this switch is set to the cor
rect type of input voltage.
External Switch open. The external switch is open causing the displayed tempera
ture to be frozen and keeping the set-point from scanning. Turn the Switch Test off
by pressing the “DOWN” button on the front panel.
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9141 Dry-well Calibrator
User’s Guide
Unstable display
The display shows
an error
Temperature cannot
be set above a cer-
tain point
AC voltage is present on the insert or
block
Wait. Allow the instrument to stabilize for a few minutes.
Proportional band may be incorrect. Refer to the proportional band on the Re
port of Calibration.
Electrical Noise. If the unit is being used in the field, take it to a different location
(calibration lab) to see if the display becomes stable. If the display is stable in the
new location, there may be electrical noise generated by equipment in the field in
terfering with the control.
Controller problem. The error messages signify the following problems with the
controller.
Err 1
- a RAM error
Err 2
- a NVRAM error
Err 3
- a Structure error
Err 4
- an ADC setup error
Err 5
- an ADC ready error
Err 6
- a defective control sensor, sensor is disconnected or shorted. Insure that
the sensor is connected.
Err 7
- a heater error, the fan will go on high speed.
Initialize the system by performing the Factory Reset Sequence described above. If
the unit repeats the error code, contact a Hart Scientific Authorized Service Center
for assistance.
Incorrect High Limit parameter. The High Limit parameter may be set below
125°C. Check this value as described in Section 7.10, Operating Parameters.
Improper Wiring. Use a wall plug tester to check the main power plug at the wall.
Power Cord. Check the cord for continuity on the ground prongs. If the resistance
is greater than one ohm, replace it.
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50
Dielectric Test. Use an ohmmeter to check the continuity between the ground
prong on the PEM and the insert. If the resistance reading is greater then three
ohms, contact a Hart Scientific Authorized Service Center for assistance.
Power up
Fuse. The unit is equipped with external operator accessible fuses. If a fuse blows,
it may be due to a power surge or failure of a component. Replace the fuse once.
DO NOT replace the fuse with one of a higher current rating. Always replace the
fuse with one of the same rating, voltage, and type. If the fuse blows a second time,
it is likely caused by failure of a component part. Contact a Hart Scientific Autho
rized Service Center (Section 1.3) for assistance.
12.2 CE Comments
12.2.1 EMC Directive
Hart Scientific’s equipment has been tested to meet the European Electromag
netic Compatibility Directive (EMC Directive, 89/336/EEC). The Declaration
of Conformity for your instrument lists the specific standards to which the unit
was tested.
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12.2.2 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.
12 Troubleshooting
CE Comments
51
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