The Criterion Instruments Limited Model DOT-5 Digital Ohmmeter is a 4-Terminal Resistance Measuring unit, primarily intended for the accurate measurement of very low resistances.
The Criterion
Instruments Limited Model DOT-5 Digital
Ohmmeter is a 4-Terminal Resistance Measuring
unit, primarily intended for the accurate
measurement of very low resistances.
Basically, it consists of a switchable
constant-current power supply and a Digital
Ohmmeter. The Model DOT-5 Digital Ohmmeter
comes complete and ready for use. It is
guaranteed against defective workmanship and
material for twelve months from date of
shipment.
MODEL DOT-5
RANGES:
FULL
SCALE
RESOLUTION
TEST
CURRENT
1 m W
1 µ W
10 A
10 m W
10 µ W
1 A
100 m W
100 µ W
1 A
1W
1 m W
100 mA
10 W
10 m W
100 mA
100 W
100 m W
10 mA
The accuracy
is better than ±0.3% of full scale
SIZE: 13W x 8H x 8D (in.)
0.1 to 5 A dc, depending on
range (regulated)
For greatest accuracy do not leave on maximum
test current for more than 15 minutes
(50% duty cycle) (4 lower ranges)
OPEN-CIRCUIT
VOLTAGE
approx. 25 V for
non-inductive resistance
approx. 45 V for transformer resistance
RESISTANCE
RANGES
(Nominal)
Six ranges
Minimum measurable resistance 1µ W
(least significant
digit on lowest range)
Maximum measurable resistance 199.9 W
Full Scale
Test Current
1.999 m W
5A
19.99 m W
5A
199.9 m W
5A
1.999 W
5A
19.99 W
1A
199.9 W
0.1A
ACCURACY
±0.3%of reading, or ±3
digits,
whichever is greater
LENGTH OF TEST
LEADS
2 m (6 ft) (approx)
supplied, with Kelvin clips
SIZE
44W x 31D x 18H cm (approx)
(23 cm high with lid closed
17W x 12D x 7H in. (approx)
(9 in. high with lid closed)
1 to 100 A dc
(70 A continous; 100 A at 50% duty cycle)
OPEN-CIRCUIT
OUTPUT
Approx. 3 V or 6 V,
depending on range
RESISTANCE
RANGES
(nominal)
Ten ranges (five ranges for
each of two current ranges)
Minimum measureable resistance 0.01µ W
(least significant
digit on lowest range)
Maximum measureable resistance 2 W
Full-scale values
on 10-A range:
0.2, 2, 20, 200, 2000 m W
Full-scale values
on 100-A range:
0.02, 0.2, 2, 20, 200 m W
ACCURACY
With the instrument fully
warmed up (3 minutes) and properly zeroed, the
resistance reading is correct to ±1%
±4 digits (±3% ±6 digits on 20-µ W range) for currents in the
range 2-10 A and 20-100 A. If the ammeter reads
between 1 and 2A (10 and 20A on high range), the
resistance error may increase to ±4%.
The ammeter will always
read the actual test current to an accuracy of
±1% ±1 digit.
Digital meters
used for both current and resistance
LEAD
RESISTANCE PERMITTED
(a) Current leads
(b) Potential leads
10m W maximum will ensure proper operation
on all ranges at 100 A. Larger resistance is
acceptable a lower test currents.
100 W maximum.
LENGTH OF TEST
LEADS
2 m (6 ft) supplied
(lower resistance than specified above)
SIZE
44W x 31D x 18H cm (23 cm
high with lid closed)
(17W x 12D x 7H in.) (9 in. high with lid closed)
