IET Labs SRac Series, User And Service Manual

Page: 10 / 17

2
SRX/SRC Series
2 Specifi cations
Chapter 2
SPECIFICATIONS
For convenience to the user, the pertinent speci fi cations are given in an
OPERATION GUIDE
, shown in Figures 1-1.
Model
SRac-
Nominal
( Ω )
Initial
adjustment to
nominal
(ppm)
Stability
1 year
(ppm)
Tempco
(ppm/°C)
Resistor
type
Calibration
uncertainty
dc
(Typical)
(ppm)
dc to ac
change at
1 kHz
(Typical)
(ppm)
Max.
power
(W)
Max.
voltage
(V)
Max.
current
(A)
Terminals
0.001
0.001 200 50 20
Manganin
strip
200
25
0.2 0.015 14
4 bp's + gnd
0.01
0.01 200 50 20
Manganin wire
100 0.6 0.15 4.5
0.1
0.1
100 20
1
Foil
60
0.3 0.17 1.7
1
1 1 10
0.3 0.54 0.54
10
10 2 5
0.6
2.45 0.245
100
100 1 5
24.5 0.024
1K
1 k 1 5
77.5 7.7 mA
10K
10 k 1 2
245 2.5 mA
100K
100 k 1 2
300 2 mA
1M
1 M 5
Wirewound
5
250 0.5 700 0.7 mA
10M
10 M 15
Film
10
2500 0.1 1000 0.1 mA
Foil resistors have a power coeffi cient of resistance (PCR) of ±5ppm at rated power due to internal heating
Foil resistors have a voltage coeffi cient (VC) of < 3ppm/V
SPECIFICATIONS
Calibration conditions:
At 23°C, low power, traceable to SI units.
Connections as indicated in table.
Terminals:
Gold plated, tellurium copper, high current, heavy
duty,low thermal-emf binding position standard 3/4 inch
spacing. A case
GROUND
terminal is provided on all
units.
Dimensions:
8.6 cm H x 10.5 cm W x 12.7 cm D (3.4"
x 4.15" x 5")
Operating temperature range: 15 to 30°C.
Transit case:
Optional
Model SRC-100
light weight transit case
with handle, suitable for transporting and storing
two units. The case provides mechanical protec-
tion and insulation from temperature chang es
during trans por ta tion or shipping.
Optional
Model SRC-100-5
light weight transit
case with handle, suitable for transporting and stor-
ing 5 SRC/SRX resistance standards.
bnc option:
Option -bnc changes Hi and Lo binding posts to 4
x bnc connectors plus the ground binding post.
SRC-100-5 Lightweight transit case for 5 standards