ECONIST OR
(8E16 & 8E24)
SPECIFICATIONS
Tolerance at 25°C:
±0.005%, ±0.01%, ±0.1%
Temperature Co-efficient:
±3ppm/°C typical over 0°C to +85°C
±5ppm maximum over –55°C to +125°C
Full Load Stability:
±35ppm/10,000hours ±50ppm/26,000 hours
No Load Stability:
±25ppm/10,000 hours
±35ppm/26,000 hours
Power Rating:
0.33 watt (+85°C) 0.25 watt (+110°C)
Maximum Continuous Working Voltage:
Up to 250V DC or peak as determined by PR
Noise: Thermal EMF:
Essentially non-measurable <0.4µV/°C typical <1.5µV/°C maximum
Encapsulation: Leads:
Moulded epoxy 22 AWG tinned copper
Windings:
Balanced multiple π for low reactance. Exclusive ‘air cushion’ technique
provides virtually stressless elements for improved performance. Non-
inductively wound. Direction of winding reversed at half turns point.
FEATURES
◆±3ppm per degree Centigrade temperature co-efficient
◆Full load stability ±50ppm maximum after three years
◆Tolerance ±0.005%, ±0.01% and ±0.1%
◆Axial leads
◆From stock in 111 popular standard values; to order in
any value from 1 ohm to 1.1 Meg
OHMIC VALUES
Econistors are available in 111 standard values from 1Ω to 1MΩ
and in any “non-standard” values from 1Ω to 1.1MΩ. Three
tolerances are available; 0.1%, 0.01% and 0.005% (0.005%
available on values of 100Ω and above only). Type 8E16
includes all values below 700KΩ; values of 700KΩ and above
are type 8E24. The types are identical except dimensionally;
Type 8E16 is 12.7mm long, Type 8E24 is 19.05mm long. Both
are manufactured using all welded construction.
Stocked in ±0.1% and ±0.01% in listed values shown below
1Ω103.90 Ω† 194.07 Ω† 680 Ω∗ 4.7K * 27K * 180K
2Ω107.79 Ω† 200.00 Ω700 Ω5.0K 30K 200K
5 Ω 109.73 Ω† 212.02 Ω† 800 Ω5.6K * 33K * 250K
10 Ω 111.67 Ω†220.00 Ω∗ 820 Ω∗ 6.0Κ 39Κ 300Κ
20 Ω 115.54 Ω†229.67 Ω†900 Ω 6.8Κ ∗ 40Κ 320Κ ∗
30 Ω 119.40 Ω†247.04 Ω†1.0 Κ 7.0Κ 47Κ ∗ 400Κ
40 Ω 120.00 Ω 250 Ω 1.2 Κ∗ 8.0Κ 50Κ 500Κ
50 Ω 123.24 Ω†270 Ω∗ 1.5 Κ 8.2Κ ∗ 56Κ ∗ 990Κ
60 Ω 125.00 Ω†300 Ω 1.8 Κ∗ 9.0Κ 60Κ 1Μ
60.25 Ω†127.07 Ω†330 Ω∗ 2.0 Κ 9.9Κ 68Κ ∗
62.50 Ω∗ 130.89 Ω†350 Ω 2.2 Κ 10.0Κ 70Κ
70 Ω 134.70 Ω†390 Ω∗ 2.5 Κ 12.0Κ ∗ 80Κ
80 Ω 138.50 Ω 400 Ω 2.7 Κ∗ 15.0Κ ∗ 82Κ ∗
84.27 Ω†150.00 Ω∗ 470 Ω∗ 3.0 Κ 18.0Κ ∗ 90Κ
90 Ω 157.31 Ω†500 Ω 3.3 Κ∗ 20.0Κ 99Κ
92.16 Ω†175.84 Ω†560 Ω∗ 3.9 Κ∗ 22.0Κ ∗ 100Κ
100 Ω 180.00 Ω∗ 600 Ω 4.0 Κ 25.0Κ 160Κ ∗
Any non-listed
value from
1ΩΩ
ΩΩ
Ω to 1.1MΩΩ
ΩΩ
Ω
available to order
RHOPOINT
COMPONENTS LTD
* Stocked in ±0.1% tolerance only. † Stocked in ±0.01% tolerance only.
A number of values listed are RTD simulation values. See page 6 for temperature equivalents.
2
Holland Road, Hurst Green, Oxted, Surrey, RH8 9AX, England
Tel: Oxted 01883717988 — Fax: Oxted 01883 712938
Outside UK Tel: +44 1883 717 988 — Fax: +44 1883 712 938
}
PRECISION WIREWOUND RESISTORS
over full temperature range;
–55°C to +125°C
ECONIST OR
(8E16 & 8E24)
ORDERING PROCEDURE EXAMPLE:
8 E 1 6 A 10 K
lll
Style and general Tolerance: R value in Ohms
specifications X = 0.005% A = 0.01% D = 0.1%
Matched pairs and ratio matched resistors are available against specific enquiries. 3
CONSTRUCTION
Econistors are wound on a proprietary multi-section bobbin
with the termination wires moulded deep into the body of the
bobbin. Each copper to resistance wire join is thus positioned
near to the centre of the resistor and spaced apart from each
other by only 2mm. This is an important factor in minimising
the effect of thermal EMFs (see separate note on thermal EMFs).
This method of construction also effectively isolates the fine
resistance wire mechanically from the termination wires. To
minimise inductance, the direction of winding is reversed at
the half turns point.
During the manufacturing process each resistor undergoes
an ageing process for a minimum of one week in a temperature
controlled oven in order to completely stabilise the winding
prior to calibration.
Econistors are encapsulated in a moulded epoxy shell which
fully seals the winding.
Resistance Wire
Highest quality copper alloy wire drawn from melts of known resistivity
and controlled temperature co-efficient.
Accuracy
Calibration is as 25°C against equipment traceable to NBS (United
States). During calibration, the electrical connection is made – 10mm
along the lead-out wires from the body. ~
Operating Temperature
The maximum operating temperature due to ambient and power
dissipation within the resistor is 160°C.
Solvent Resistance
The body material and identification marking is resistant to all
commonly used PC board solvents.
Lead Pull Strength
2kg (limited only by inherent strength of copper lead material).
Resistance of Termination Leads
Type 8E16 = 0.52m Ohms/cm
Type 8E24 = 0.33m Ohms/cm
Voltage Co-efficient
Essentially zero
Manufacturing
The highest quality materials are used; all processing is performed in
temperature/humidity controlled “clean rooms”, each step is carefully
monitored.
Thermal EMFS
The temperature difference between the two copper to resistance wire
joins is the critical factor. If the two junctions are at the same
temperature, then the effect of thermal EMFs is minimised.
The construction of Econistors is such that the two junctions are not
more than 2mm apart, thus reducing any possibility of temperature
difference almost to zero. This largely negates the effect of thermal
EMFs in Econistors.
The thermal EMF of the resistance material to copper join for
Econistors is typically <0.4µV/°C.
PRECISION WIREWOUND RESISTORS
