Fluke Thermometer 50D User Manual

50S & 50D  
Thermometer  
Calibration Information  
WWarning  
These service instructions are for use by qualified personnel only. To avoid  
electric shock, do not perform any servicing unless you are qualified to do so.  
Introduction  
This document contains specifications, general maintenance information, performance tests, calibration  
procedures, and a list of user replaceable parts for the Fluke 50S and 50D Thermometers, hereafter referred  
to as “the thermometer”.  
Service  
To contact Fluke, order parts, or locate a Fluke service center, call one of the following telephone numbers:  
USA: 1-888-99-FLUKE (1-888-993-5853)  
Canada: 1-800-36-FLUKE (1-800-363-5853)  
Europe: +31 402-675-200  
Japan: +81-3-3434-0181  
Singapore: +65-738-5655  
Anywhere in the world: +1-425-446-5500  
Or, visit Fluke's Web site at www.fluke.com.  
Warranty  
This Fluke product will be free from defects in material and workmanship for one year from the date of  
purchase. This warranty does not cover fuses, disposable batteries or damage from accident, neglect, misuse  
or abnormal conditions of operation or handling. Resellers are not authorized to extend any other warranty  
on Fluke’s behalf. To obtain service during the warranty period, send your defective tester to the nearest  
Fluke Authorized Service Center with a description of the problem.  
THIS WARRANTY IS YOUR ONLY REMEDY. NO OTHER WARRANTIES, SUCH AS FITNESS FOR  
A PARTICULAR PURPOSE, ARE EXPRESSED OR IMPLIED. FLUKE IS NOT LIABLE FOR ANY  
SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, ARISING  
FROM ANY CAUSE OR THEORY. Since some states or countries do not allow the exclusion or limitation  
of an implied warranty or of incidental or consequential damages, this limitation of liability may not apply to  
you.  
Fluke Corporation  
P.O. Box 9090  
Everett WA  
Fluke Europe B.V.  
P.O. Box 1186  
5602 B.D.  
98206-9090  
Eindhoven  
The Netherlands  
PN 1281009  
October 1999 Rev.1, 3/03  
©1999-2003 Fluke Corporation. All rights reserved. Printed in U.S.A.  
All product names are trademarks of their respective companies.  
1
 
Specifications  
Specifications  
General  
Weight  
280 g (10 oz)  
Dimensions  
(without holster)  
2.8 cm × 7.5 cm × 16.6 cm  
(1.1 in × 3 in × 6.6 in)  
Battery  
Standard 9 V battery (NEDA 1604, 6F22, or 006P)  
Protection  
Class III as defined in IEC 348, Safety Requirements for Electronic Apparatus  
Environmental  
Operating Temperature  
Storage Temperature  
0 oC to +50 oC (+32 oF to +122 oF)  
40 oC to +60 oC (40 oF to +140 oF)  
0 % to 90 %: 0 oC to 35 C (+32 oF to +95 oF)  
o
Humidity  
0 % to 70 %: 0 oC to 50 oC (+32 oF to +122 oF)  
Electrical  
K-type: 200 oC to +1370 oC (328 oF to +2498 oF)  
J-type: 200 oC to +760 oC (328 oF to +1400 oF)  
Measurement Range  
Display Resolution  
Low: +1.0 oC or +1.0 oF  
High: +0.1 oC or +0.2 oF  
K-type: ±(0.1 % of reading + 0.7 oC) [±(0.1 % of reading + 1.3 oF)]  
J-type: ±(0.1 % of reading + 0.8 oC) [±(0.1 % of reading + 1.4 oF)]  
Measurement Accuracy  
Temperature  
Coefficient  
0.01 % of reading + 0.03 oC (0.03 oF) for [ambient temperatures from +18 oC to +28 oC  
(+64 oF to +82 oF) ]  
Maximum Differential Common Mode 1 V (Maximum voltage difference between T1 and T2)  
Voltage  
Temperature Scale  
Certification  
IPTS-68  
P, $  
Applicable Standards  
NBS 125, IEC 584  
Accuracy is specified for ambient temperatures between +18 oC (+64 oF) and +28 oC (+82 oF) for a period of 1 year. The above  
specifications do not include thermocouple error.  
Accuracy is unspecified when the input lead length is resonant with the interfering frequency.  
Basic Maintenance  
Basic maintenance required by the thermometer is discussed in this section.  
Cleaning the Thermometer  
Caution  
To avoid damaging the thermometer, do not use aromatic hydrocarbons or  
chlorinated solvents for cleaning. These solutions react with the plastics  
used in the thermometer.  
Do not allow the LCD to get wet.  
Do not remove any of the lubricant from the input terminals.  
3
 
50S & 50D Thermometer  
Calibration Information  
Clean the thermometer case with a mild detergent and water.  
The pca may be washed with isopropyl alcohol or deionozed water and a soft brush. Dry the pca with clean  
dry air at low pressure, then bake it at 50 oC for 24 hours.  
Disassembly/Reassembly  
Thermometer disassembly is necessary to replace the battery and some interior parts (see “Replaceable  
Parts”, later in this document). Refer to Figure 1 when disassembling and reassembling the thermometer.  
To disassemble the thermometer:  
1. Turn the thermometer OFF if necessary.  
2. Loosen the four bottom case screws and remove the top case.  
To reasemble the thermometer:  
1. Replace the top case.  
2. Tighten the four bottom case screws.  
zf01f.eps  
Figure 1. Thermometer Disassembly and Reassembly (50D is shown)  
4
 
Basic Maintenance  
Changing the Battery  
WWarning  
Replace the battery as soon as the low battery indicator (N) appears. The  
possibility of false readings increases when the battery is not fully charged.  
False readings can lead to personal injury.  
To avoid electrical shock, disconnect the thermocouple(s) before opening  
the case.  
Caution  
Do not attempt to recharge the battery.  
To prevent explosion, do not dispose of the battery in fire.  
Follow local laws or regulations when disposing of batteries.  
To replace the battery, refer to Figure 2 and the assembly procedures located previously in this document.  
zf02f.eps  
Figure 2. Replacing the Battery (50D is shown)  
5
 
50S & 50D Thermometer  
Calibration Information  
Required Test Equipment  
Table 2 lists the required test equipment needed to perform the performance test and calibration procedures  
for the 50S and 50D thermometers. If the required equipment is not available, instruments with equivalent  
specifications may be used.  
Table 2. Required Test Equipment  
Test Equipment  
Required Characteristics  
Recommended Model  
Fluke 87 Series IV Digital  
Multimeter  
DMM  
DC Voltage Accuracy: 0.5%  
Temperature Probe  
Accuracy: Certified to ± 0.2 oC ambient  
Fluke Model 80T-150U  
Output Voltage 0 to 10 V  
Accuracy: 0.025%  
DC Voltage Calibrator  
Elastomeric Switch Pad  
Resolution: 10 µV  
Fluke 5520A  
Fluke Part Number 680686  
Fluke 80CK-M  
Thermocouple Connector  
Thermocouple Connector  
For K-type thermocouple  
For J-type thermocouple  
Fluke Part Number 779942  
80CJ-M  
Fluke Part Number 833046  
Thermocouple Wire  
(K or J Type)  
Standard  
Omega  
Dewar Flask/Cap  
1-pint capacity  
Thermos  
Mercury Thermometer  
(either oC or oF)  
0.02 oC resolution  
0.05 oF resolution  
Princo Model ASTM56C  
Princo Model ASTM56F  
Performance Tests  
Performance tests are recommended for incoming inspection, periodic maintenance, and for verifying the  
thermometer’s specifications. If the thermometer fails any part of the performance tests, calibration and/or  
repair is indicated.  
Use the following procedure to prepare the thermometer before beginning the performance tests or  
calibration procedures.  
1. Allow the thermometer to stabilize to room temperature, 23 oC ± 5 oC (73 oF ± 9 oF).  
2. Check the battery and replace it if necessary.  
Display Test  
Turn the thermometer on while pressing the HOLD button. All display segments are shown until the HOLD  
button is released. Check that all the display segments are showing as in Figure 3.  
Note  
Because pressing the HOLD button during power-up activates one of the thermometers other  
functions, take care to return the instrument to its normal function (if necessary).  
6
 
Performance Tests  
50S Display  
50D Display  
J K  
- +  
J K  
- +  
HOLD  
MIN MAX HOLD REC  
F
C
F
C
T1  
T2  
T1-T2  
zf03f.eps  
Figure 3. Display Segments  
Wide Range Performance Test Procedure  
This test verifies the instrument specifications. If the instrument fails this test, perform the calibration  
procedure. If the unit continutes to fail, it should be taken to a Fluke service center.  
Ice Bath Construction  
To begin the wide range performance test procedure, first construct an ice bath using the following steps:  
1. Prepare a Dewar Flask by drilling two holes in its cap to accept the thermometer and thermocouple  
wires, or use a standard laboratory cork.  
2. Fill the Dewar Flask with shaved or crushed ice made from distilled water.  
3. Fill the Dewar Flask with enough distilled water so that the ice turns to slush, but do not add enough  
water to float the ice.  
Note  
As the ice melts, siphon off the excess water and add more ice. Allow approximately 5 to 10  
minutes for the water to drop back to the freezing point.  
4. Replace the Dewar Flask cap or cork, and insert the thermocouple wires as shown in Figure 4.  
7
 
50S & 50D Thermometer  
Calibration Information  
50S or 50D  
Thermometer  
Thermocouple wire  
+
_
Ice bath  
5520A  
Copper wire  
zf05f.eps  
Figure 4. Ice Bath Equipment Connections  
Ice Bath Test  
Use the following procedure to test the thermometer. This test should be conducted on both thermocouple  
inputs of the 50D.  
1. Connect the equipment as shown in Figure 4.  
2. Insert the Mercury Thermometer to the same depth as the thermocouple wires and verify that the ice  
bath temperature is 0.0 oC ± 0.1 oC.  
3. Short (or apply 0 mV) to the copper wires at the 5520A Calibrator.  
4. Verify the thermometer reads 0.0 oC ± 0.4 oC.  
5. If this test fails, reposition the thermocouple wires and Mercury Thermometer in the ice bath and repeat  
steps 2-4. If the test continues to fail, perform the calibration procedure, located later in this document.  
6. Remove the short applied in step 3.  
7. Using Table 3 (for the corresponding thermocouple type), obtain an output from the 5520A equal to the  
first value of the “Input Voltage (mV DC)” column, and verify that the thermometer reads within the  
limits specified.  
8. Repeat these steps for the remaining voltages in the “Input Voltage (mV DC)” column.  
9. Disconnect the thermocouple from the input terminals. This completes the ice bath test.  
8
 
Calibration  
Table 3. Performance Test Values  
Thermocouple  
Type  
Input Voltage  
(mV DC)  
Display Reading  
oC  
oF  
K
K
K
K
-5.587  
-182.0 ±(0.9)  
-89.0 ±(0.8)  
530.0 ±(1.2)  
1355.0 ±(2.1)  
-295.6 ±(1.6)  
-128.2 ±(1.4)  
986.0 ±(2.3)  
2471.0 ±(3.8)  
-3.211  
21.919  
54.297  
J
J
J
-7.824  
13.997  
39.442  
-197.0 ±(1.0)  
258.0 ±(1.1)  
705.0 ±(1.5)  
-322.6 ±(1.7)  
496.4 ±(1.9)  
1301.0 ±(2.7)  
Calibration  
When calibrating the thermometer, refer to Figure 5 for the proper setup connections and Figure 6 for  
adjustment locations.  
Caution  
When directed to short a switch grid in the following procedures, use only the  
elastomeric switch pad that is supplied as pca damage may occur if a hard tool  
is used.  
Thermometer Calibration  
1. Turn the thermometer off and remove the top case leaving the Main PCA in the bottom case.  
2. Simultaneously short the TP1 switch grid and turn on the thermometer by shorting the ON/OFF switch  
grid. Hold the elastomeric switch pad on TP1 for at least 3 seconds after the thermometer turns on. This  
puts the thermometer into the Thermocouple Calibration mode.  
3. Allow the thermometer to stabilize at room temperature, 23 oC ± 5 oC (73 oF ± 9 oF).  
4. Select oC mode. Select T1 if the thermometer is a Fluke 50D.  
5. Adjust the 5520A for 0.00000V. Connect the 5520A output to the TP1 input.  
6. Allow the thermometer reading to stabilize. Refer to Figure 6 and adjust the T1 offset adjustment (R7)  
for a display reading of 25.2 oC ± 0.1 oC.  
If you are calibrating a Fluke 50S, skip the next two steps.  
7. Leave the 5520A adjusted for 0.00000 V. Connect the 5520A output to the T2 input and select the T2  
function.  
8. Allow the reading to settle and adjust the T2 offset adjustment (R13) for a display reading of 25.2 oC ±  
0.1 oC.  
9. Adjust the 5520A for 53.807 mV output.  
10. Allow the reading to stabilize and adjust (R21) for a display reading of +1370.0 oC ± 0.4 oC.  
11. Disconnect the thermometer from the 5520A. Turn the thermometer off by shorting the ON/OFF switch  
grid.  
12. With an elastomeric switch pad in both hands, use the left pad to short out the TP2 grid, and use the  
right pad to first turn on the instrument and then quickly short out the VIEW switch grid. Hold this  
9
 
50S & 50D Thermometer  
Calibration Information  
position until the display is locked in self-test (all LCD segments on). This thermometer is now in the  
Reference Junction Sensor calibration mode. Shorting out the VIEW switch grid turns off a filter so that  
the reading stabilizes immediately.  
13. Using the 80T-150U and the Fluke 87 Series IV Digital Multimeter (DMM), measure the reference  
junction transistor temperature by placing the 80T-150U probe tip against Q1, located in the middle hole  
of the isothermal block. Wait for the temperature reading to stabilize.  
14. Adjust R16 for a temperature reading that is the same as displayed on the DMM.  
15. Turn the thermometer OFF by shorting the ON/OFF switch grid, and reattach the top-case.  
50S or 50D  
Thermometer  
+
_
Copper  
wire  
5520A  
zf07f.eps  
Figure 5. Calibration Connections  
10  
 
Calibration  
FLUKE 52-1601  
zf09f.eps  
Figure 6. A1 Main PCA Adjustments  
Optimizing Thermometer Performance in the Negative Temperature Range  
Perform the following steps to optimize the thermometer performance in the negative temperature range:  
1. Put the thermometer in normal operating mode. Normal operation can be achieved by turning the  
thermometer OFF and then ON. No other thermometer buttons should be pressed during the power cycle  
operation.  
2. Insert a known good thermocouple in an ice bath (see “Ice Bath Construction” earlier in this document).  
3. Insert the Mercury Thermometer to the same depth as the thermocouple wires verifying the ice bath  
temperature is 0.0 oC ± 0.1 oC.  
4. Connect the other end of the thermocouple wire to the T1 input of the thermometer and allow the  
instrument reading to stabilize.  
5. Slowly, and in small increments, adjust R7 (T1 offset) until the thermometer reading matches the  
Mercury Thermometer reading. Allow the thermometer reading to stabilize and repeat the adjustment as  
necessary until a stable and correct reading can be attained.  
6. Repeat steps 4 and 5 for R13 (T2 offset, Fluke 50D only).  
Thermocouple Input Calibration (Optional)  
Note  
This adjustment procedure counteracts the adjustments made in the “Optimizing Performance  
in the Negative Temperature Range” section of this document.  
This procedure optimizes the 50S or 50D for measurement with a specific thermocouple.  
Perform the thermocouple input calibration using the following procedure:  
1. Construct an ambient temperature lag bath as shown in Figure 7.  
2. Connect the thermocouple to the thermometer input terminals.  
3. Select the applicable switch postion (T1 or T2) and temperature scale (oC or oF).  
4. Insert the probe into a room temperature lag bath.  
11  
 
50S & 50D Thermometer  
Calibration Information  
5. Allow the system to stabilize, then adjust T1 or T2 offset adjustments for a temperature display equal to  
the reading of the lag bath reference thermometer.  
6. Calibration of the thermometers is complete. Disconnect all test equipment from the instrument.  
50S or 50D  
Thermometer  
_
+
Thermocouple wire  
Mercury  
thermometer  
(0.02°C resolution)  
Lag bath  
(room temperature  
water)  
Immersed to  
approximately  
same depth  
zf06f.eps  
Figure 7. Room Temperature Lag Bath  
12  
 
Replaceable Parts  
Replaceable Parts  
Refer to Table 4 for all replacement part numbers and Figure 8 for part locations. Unless specified in the  
“Model Number” column, all parts are for all units. To order replaceable parts, see the “Service Centers”  
section of this manual.  
Table 4. 50S and 50D Replaceable Parts  
Fluke  
Item  
Number  
Part  
Number  
Model  
Number  
Qty.  
Description  
1
1
778191  
778209  
MAIN PCA  
MAIN PCA  
50S  
50D  
1
2
3
4
5
1
4
1
4
696534  
832246  
519116  
448456  
BATTERY, PRIMARY, 9V, 0-15MA  
All  
SCREW, PH, P, AM THD FORM, STL, 5-14, .750  
SCREW, PH, P, THD FORM, STL, 4-24, .250  
SCREW, PH, P, AM THD FORM, STL, 4-14, .375  
All  
All  
All  
1280490 CASE, TOP  
1280483 CASE, TOP  
50S  
50D  
6
1
1280766 CASE, BOTTOM  
1280753 CASE, BOTTOM  
50S  
50D  
7
8
9
1
1
1
646653  
BRACKET, LCD  
All  
1280151 MASK, BRACKET, FLUKE 50S  
1280160 MASK, BRACKET, FLUKE 50D  
50S  
50D  
10  
11  
12  
13  
14  
15  
16  
1
2
1
4
1
1
1
745794  
649632  
761924  
640565  
844340  
791343  
ISOTHERMAL BLOCK  
All  
All  
All  
All  
All  
All  
CONNECTOR , ELASTOMERIC, LCD TO PWB, 1.900 L  
BOTTOM SHIELD, MYLAR  
FOOT, NON-SKID  
LABEL, WINDOW  
WINDOW, LCD (BLANK)  
742205  
741314  
LCD FLUKE-51, LCD, 5 DIGIT, TEMPERATURE, MULTIPLEXED  
LCD FLUKE-52, LCD, 5 DIGIT, TEMPERATURE, MULTIPLEXED  
50S  
50D  
1
2
50S  
Not shown  
Not shown  
Not shown  
773135  
THERMO COUPLE ASSY, T/C ASSY, K-TYPE, BEADED, MOLDED-PLUG 50D  
1
1
1278540 MULTI-LANGUAGE, FLUKE 50S & 50D USERS MANUAL  
890298 HOLSTER & FLEXSTAND ASSY, YELLOW  
All  
All  
13  
 
50S & 50D Thermometer  
Calibration Information  
15  
6
9
4
16  
2
10  
4X  
5
1
12  
7
8
11  
2X  
4X  
13  
3
4X  
zf08f.eps  
Figure 8. Exploded View Diagram (Model 50D is Shown)  
14  
 

Electro Voice Portable Speaker S 80A User Manual
Excalibur electronic Motorized Toy Car 904BK Black User Manual
Extron electronic Indoor Furnishings AAP 301 User Manual
Fagor America Range RFA 244 DF User Manual
Field Controls Water System CW HD 2 User Manual
FMI Indoor Fireplace CGCFTNA User Manual
Frigidaire Air Conditioner THRU THE WALL AIR CONDITIONER User Manual
Garland Range C0836 13 User Manual
GE Refrigerator 162D9617P008 User Manual
Gianni Industries Door GL 1200S series User Manual