Ultra Precision Bulk
Metal Film Resistors
4800 Series
•Tolerances down to 0.005%
•Current noise and distortion below level
of practible measurement
•Low thermal e.m.f
•Ideal resistor for precision instrumentation
•Use of bulk metal gives superior stability
•Planar construction gives low residual
capacitance and inductance
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Resistance tolerance See table 1 below
21/2084
52.0
K65ot001
002
5
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Values E24 and E96 preferred Any value to order
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General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Electrical Data
Table 1. Resistance Range (ohms) and Tolerance (%)
07.11
A subsidiary of
TT electronics plc
Welwyn Components
5084408423/21/2084)edoc( ecnareloT
K003 ot R56K002 ot R001K001 ot R002)E( 500.0
K003 ot R33K002 ot R05K001 ot R001)L( 10.0
K003 ot R71K002 ot R52K001 ot R05)P( 20.0
K003 ot R8K002 ot R01K001 ot R52)W( 50.0
K003 ot R3.3K002 ot R5K001 ot R01)B( 1.0
K003 ot R7.1K002 ot R2K001 ot R5)C( 52.0
K003 ot R6.0K002 ot R01K001 ot R2)D( 5.0
K003 ot R33.0K002 ot R5.0K001 ot R1)F( 0.1
Construction
The resistor element is an etched bulk metal foil, bonded to
an alumina substrate. Connections to the foil are made by
copper wires welded to the foil to minimise thermal e.m.f.
Before encapsulation, the resistor element is coated with
silicone rubber to isolate the element from mechanical stress
which would adversely affect the carefully balanced
construction and result in poor resistance/temperature
characteristics.
Ultra Precision Bulk Metal
Film Resistors
4800 series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
187
Dimensions (mm) & Weight (g)
Type L max H max W max T min d nom S nom Wt. nom
4802 8.9 10.2 3.8 30 0.6 5.1 1
4812 7.5 8 2.5 30 0.6 5.1 0.6
4804 15.2 13.2 3.8 30 0.6 10.2 1.5
4805 22.6 13.2 3.8 30 0.6 17.8 2
4832 9.7 5.4 9.7 30 0.6 1.5 1.1
Physical Data
L
4802/12/04/05
4832
W
S
H
Td dia
L
HT
d
WS
07.11
Welwyn Components
Actual
Maximum Typical
Load at commercial rating: 1000 hours at 70°C ∆R% 0.05 0.02
Dry heat: 1000 hours at 155°C ∆R% 0.05 0.02
Shelf life: 12 months at room temperature ∆R% 0.0025
Derating from rated power at 70°C Zero at 155°C
Short term overload ∆R% 0.01 0.005
Climatic category 55/155/56
Climatic ∆R% 0.05 0.03
Long term damp heat ∆R% 0.05 0.03
Temperature rapid change ∆R% 0.01 0.005
Resistance to solder heat ∆R% 0.01 0.005
Vibration and bump ∆R% 0.01 0.005
Noise. (in a decade of frequency) µV/V Below level of
Voltage coefficient of resistance ppm/V practicable measurement
Insulation Resistance ohms >1000M
Inductance µH 0.2 0.08
Capacitance pF 1 0.5
Terminations
Material Solder coated copper wire
Strength The terminations meet the requirements of
IEC 68.2.21.
Solderability The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2.
Marking
Type reference, resistance value, tolerance and date code are
legend marked. The resistance value conforms to IEC 62.
Solvent Resistance
The protection will withstand all normal industrial solvents
suitable for cleaning printed circuit boards.
Packaging
All components are supplied loose packed in either plastic bags
or panel boxes. Quantity per box will depend on resistor size.
Performance Data
Ultra Precision Bulk Metal
Film Resistors
4800 series
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 07.11
Welwyn Components
Ordering Procedure
Example: 4812 at 73.2 kilohms and 0.01% tolerance -
4 8 1 2 – 7 3 K 2 L I
Type
Value (use IEC62 code)
Tolerance (use IEC62 code)
E
0.005%
B
0.1%
L
0.01%
C
0.25%
P
0.02%
D
0.5%
W
0.05%
F
1%
Packing
I
Bag / Box
Standard
