BS407 AIM-TTI INSTRUMENTS, BS407 Datasheet
![MICRO OHM METER](/photos/23/51/235162/42263923_sml.jpg)
BS407
Manufacturer Part Number
BS407
Description
MICRO OHM METER
Manufacturer
AIM-TTI INSTRUMENTS
Datasheet
1.BS407.pdf
(1 pages)
Specifications of BS407
Resistance Measuring Range
1µR To 20kR
Resolution
1µohm
Test Current
250mA
External Height
82mm
External Width
219mm
External Depth
240mm
Weight
1.5kg
Svhc
No SVHC (15-Dec-2010)
Accuracy %
0.1%
External
RoHS Compliant
Resolution (ohm)
1µohm
Rohs Compliant
NA
A dedicated but versatile instrument
The BS407 is an instrument which is fully optimised for the task of accu-
rate measurement of low resistances with a best resolution of 1µ .
Most multimeters offer a best resolution which is at least one thousand
poorer than this. A very high resolution multimeter may attempt to re-
solve fairly low resistances, but it does so by resolving extremely low volt-
ages (typically one nano-volt per micro-ohm), making it subject to severe
errors from thermal emf effects and noise.
In contrast, the BS407 generates sufficient test voltage across the un-
known resistance to combat noise and reduce thermal emf effects to
manageable levels. Current reversal can then be used to eliminate any
remaining thermal offset.
Rapid 4-terminal measurement
The BS407 uses a four terminal measurent system via high quality Kel-
vin Clip leads (supplied).
For speed and convenience front panel switches are provided for current
diversion (allowing in-situ zero adjustment) and current reversal (for
identifying thermal emf errors). An LED indicator warns of open circuit
leads thus preventing spurious results from being recorded.
Battery operation with built-in charger
The BS407 is a fully portable instrument which operates from NiMh re-
chargeable batteries. The battery charger is built into the instrument and
can be operated continuously during bench use.
Wide measurement range
The BS407 has eight push-button selected decade measurement
ranges from 1.999m up to 19.99k .
This unusually wide range makes it suitable for a greater variety of appli-
cations than other micro-ohmmeters.
A front panel operated ‘clamp’ switch is available to limit the maximum
voltage across the unknown to 20mV. This is a requirement for the mea-
surement of switch contact resistances to international standards.
High resolution and accuracy
With a lowest range of 1999µ the BS407 can resolve one micro-ohm.
Precision analogue circuitry ensures a high measurement accuracy of
up to 0.1% of reading ± 1 digit.
BS407 Wide range precision micro-ohmmeter
Designed and built in the EEC by:
High basic accuracy of 0.1%
Wide measurement range of 1 micro
Current reversal switch for detecting thermal emf effects
Current diversion switch for easy zero setting
Four terminal measurement using Kelvin clip leads
Battery operation with built-in charger
Switchable 20mV clamp for ‘dry circuit’ testing
Glebe Road, Huntingdon. Cambs. PE29 7DR United Kingdom
e-mail: sales@tti-test.com Web: http://www.tti-test.com
T T
Off
On
Tel: +44 (0)1480 412451 Fax: +44 (0)1480 450409
Operate
Zero Clamp
Set
BS407 PRECISION MILLI/MICRO OHMMETER
20mV
Thurlby Thandar Instruments Ltd.
Polarity
250mA 50mA 10mA 5mA
1999
19.99 199.9
ZERO ADJUST
m
THURLBY THANDAR INSTRUMENTS
Force Current
1999
500 A
19.99 199.9
50 A
Force on
Charge
50 A
1999 19.99
to 20k
10 A
k
50
+
1
UNKNOWN
FORCE
SENSE
to 20 k
_
RANGES AND ACCURACY
Accuracies apply over a temperature range of 18
warm-up period of 30 minutes, and with the test connections in thermal
equalibrium. Specificied accuracy applies for a period of one year.
FACILITIES
20mV Clamp
Operated by front panel switch. Limits the open circuit voltage across
the unknown to 20mV (+0mV, -4mV) for “dry circuit” testing of switch
and relay contacts. Not available on the 2000 and 20k ranges.
Reverse Polarity
Operated by front panel switch. Reverses the polarity of the test cur-
rent, enabling thermal emf effects to be detected and quantified.
Set Zero
Operated by non-latching front panel switch and rotary offset control.
Diverts the test current way from the unknown allowing zero adjust-
ment to be undertaken with the test leads in place.
MEASUREMENT SOURCE
Source EMF
Compliance
Compliance is the maximum voltage that can be tolerated from additional
resistance in series with the force connections
PROTECTION
The instrument is protected against the back-emf of its own test current
from any inductance.
The instrument is protected against external voltage sources delivering
up to one amp. Protection against greater abuse is provided by
non-flamable fusible resistors.
POWER SOURCE
Battery
Four internal Ni-MH cells (non removable). Operating time depends
upon the test current flowing - >150 hours with no test current, > 8
hours with maximum test current (1999µ range). Low battery indica-
tion in display.
AC Line
Built-in battery charger allows instrument operation while re-charging.
Nominal re-charge time 16 hours.
GENERAL
Display:
Casing:
Power:
Operating Range: +5
Storage Range:
Environmental:
Electrical Safety:
EMC:
Size:
Weight:
ACCESSORIES
SUPPLIED
Kelvin Test Clip Leads, Operating Manual, IEC Mains Lead
OPTIONAL
Carrying Case
Thurlby Thandar Instruments Ltd. operates a policy of continuous development
and reserves the right to alter specifications without prior notice.
19.99 m
199.9 m
1999 m
19.99 k
1999 µ
19.99
199.9
1999
Range
Resolu-
100 m
100 µ
10 m
10 µ
1 m
1 µ
10
tion
1
18 mV ± 2mV with 20mV Clamp Active
< 6V with 20mV Clamp Inactive
> 1V (> 0.5V on 1999µ range).
3.5 digit LCD with 12.5mm characters.
ABS casing with metal tilt stand giving 15
230V or 115V ±14% 50/60Hz, adjustable internally;
-10
Indoor use at altitudes to 2000m, Pollution Degree 2.
Complies with EN61010-1.
Complies with EN61326.
220(W) x 82(H) x 230(D) mm, (10.3 x 3.4 x 9.2")
excluding feet and tilt stand.
1.3 kg (3lb).
20VA max. Installation Category II.
o
C to + 40
o
C to +65
Test Cur-
250 mA
500 µA
50 mA
10 mA
50 µA
50 µA
10 µA
5 mA
rent
o
o
C, 20% to 80% RH.
C
F.S. Volt-
100 mV
200 mV
500 µV
10 mV
10 mV
10 mV
1 mV
2 mV
age
± 0.1% r ± 0.4% scale
± 0.1% r ± 0.2% scale
± 0.1% r ± 0.1% scale
± 0.1% r ± 0.1% scale
± 0.1% r ± 0.1% scale
± 0.1% r ± 0.1% scale
± 0.1% r ± 0.1% scale
± 0.1% r ± 0.2% scale
o
C to 28
Accuracy
o
C after a
o
angle.