Miniohms are only 7.94mm long with a diameter of 3.97mm,
yet they incorporate advanced design and manufacturing
features which provide unsurpassed accuracy , stability , load life
and reliability. Each Miniohm undergoes three separate
complete tests during manufacture including an accelerated
ageing thermal shock procedure.
FEATURES
◆Miniature size
◆Temperature co-efficient ±3ppm per °C
◆Full load stability ±50ppm maximum after three years
◆Tolerance ±0.01% and ±0.1%
OHMIC VALUES
Miniohms are available in 78 standard values from 10Ω to
100KΩ and in any ‘non-standard’ value from 10Ω to 200kΩ.
CONSTRUCTION
Miniohms are made in an identical way to Econistors,
incorporating the same all-welded construction. For a full
description please refer to the notes and diagrams on the
previous page.
MINIOHM
(5E10) Precision Wirewound Resistor
4
Stocked in ±0.1% and ±0.01% in listed values shown below
10 Ω180 Ω* 680 Ω* 3.3K * 12K * 60K
20 Ω200 Ω700 Ω3.9K * 15K * 68K *
30 Ω220 Ω* 800 Ω4.0K 18K * 70K
40 Ω250 Ω820 Ω* 4.7K * 20K 80K
50 Ω270 Ω* 900 Ω5.0K 22K * 82K *
60 Ω300 Ω1.0 K 5.6K * 25K 90K
62.5 Ω* 330 Ω* 1.2 K* 6.0K 27K * 99K *
70 Ω350 Ω1.5 K 6.8K * 30K 100K
80 Ω390 Ω* 1.8 K* 7.0K 33K *
90 Ω400 Ω2.0 K 8.0K 39K
100 Ω470 Ω* 2.2 K* 8.2K * 40K
120 Ω500 Ω2.5 K 9.0K 47K *
125 Ω* 560 Ω* 2.7 K* 9.9K * 50K
150 Ω* 600 Ω3.0 K 10.0K 56K *
* Stocked in ±0.1% tolerance only.
Any non-listed
value from
10ΩΩ
ΩΩ
Ω to 200KΩΩ
ΩΩ
Ω
available to order
ORDERING PROCEDURE EXAMPLE:
5 E 10 A 10 K
III
Style and Tolerance R value
general A = 0.01% in Ohms
specifications D = 0.1%
Matched pairs and ratio matched resistors are
available against specific enquiries.
SPECIFICATIONS
Temperature Co-efficient: Tolerance at 25°C:
±3ppm/°C typical over 0°C to +85°C ±0.01%, ±0.1%
±5ppm maximum over –55°C to +125°C
Full Load Stability:
±35ppm/10,000hours
±50ppm/26,000 hours
No Load Stability:
±25ppm/10,000hours
±35ppm/26,000 hours
Power Rating: Noise:
0.2 watt (+85°C) Essentially non-
measurable
0.14 watt (+110°C)
Maximum Voltage: Encapsulation:
175V DC or AC peak Moulded epoxy
Thermal EMF: Leads:
<0.4µV/°C typical 24 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.
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 Miniohms 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 Miniohms.
The thermal EMF of the resistance material to copper join for
Miniohms is typically <0.4µV/°C.
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RHOPOINT COMPONENTS LTD
over full temperature range; –55°C to +125°C
