Model 2768 is a Precision bridge used for the exact determination of resistance in the 100 MΩ to the 110MΩ Range with an accuracy of 0.01 to 0.05%. Since this instrument includes a high-sensitivity transistorized galvanometer and bridge power source, no auxiliary device is required.
Superior resistor aliment
Minimized contact resistance
Guarding and shielding
Materials of high insulation resistance and low absorption are employed. Guard circuits are provided to insure stable operation even In highly humid atmospheres. The instrument is housed in a {grey} metal case to assure -to operator of excellent shielding.
Heat-insulated pushbutton keys
If the operator’s body temperature were carried to the galvanometer sensitivity control keys, a temperature difference would arise at the contact point and produce thermal emf resulting in measurement error. To eliminate this effect, the pushbutton keys for the galvanometer sensitivity control are heat-insulated with phenol resin.
Description
Precision Wheatstone Bridge
Measuring Range
0.1Ω to 11.1Ω
Measuring Method
Null method (in-line readout).
Measuring Arm
0 to 11, 111Ω adjustable in 0.1Ω steps, (consists of five decades; 1,000Ω x 10 + 100Ω x 10Ω x 10 + 1Ω x 10 + 0.1Ω x 10)
Multiplier
x 100mΩ, x 1Ω, x 10Ω, x100Ω, x1kΩ, x 10kΩ, x100kΩ, x1MΩ, and x10MΩ
Accuracy
(at 23±2°, less then 75%) x 100mΩ range ±0.5mΩ, x 1Ω range (±0.02% of setting +0.5mΩ) x 10Ω range, x 100kΩ & 1MΩ ranges ±0.02% of setting x100Ω x 1kΩ & x 10kΩ ranges &
Maximum Allowable Input
0.2W continuously for ratio arm, 0.2W continuously per element of Measuring arms
Insulation Resistance
More than 100MΩ at 500V DC between the electric circuit and the case
Dielectric Strength
500V AC for one minute between electric circuit and case
Galvanometer (Built-In)
Max sensitivity approx. 10µV/div. (provided with a sensitivity adjuster)
Galvanometer Power Source
Single 9V battery (JIS 6F22 or equivalent)
Galvanometer Battery Life
Approx. 300 Hours
Case
Grey metal Case, with plastic feet and carrying handles
Bridge Power Source (Built-In)
Power source range - 1.5/3/6/15V selectable, Power source battery - four 1.5V batteries (JIS R20P, ANSI D, Mono 1.5V or equivalent) and a single 9V battery (JIS 6F22, ANSI 6F22, Energieblock 9V or equivalent)
