QJ55 Type DC Current Comparison Ceremony BridgeDetailed product description：

QJ55 DC Current Comparison Ceremony Bridge

Description
The QJ55 DC current comparison bridge is a wide range bridge used for comparing and verifying standard resistors, DC resistance boxes, or calibrated decade resistors below 0-106 Ω.

Main technical parameters:

1. Accuracy of standard resistance measurement:

Measurement range (Ω)	ten-4	ten-3~10-1	ten0~10four	tenfive	tensix
accuracy	2×10-5	2×10-6	1×10-6	2×10-6	2×10-5

2. The value calculated by the formula:

measurement range	Error formula	requirement
ten-4Ω	±2×10-6	DC magnetic potential ≥ 10 ampere turns Voltage drop on the resistor ≥ 10mV
ten-2Ω, 10-3Ω	±1×10-6	DC magnetic potential ≥ 30 ampere turns Voltage drop on the resistor ≥ 30mV
ten-1Ω ~10-4Ω	|Δ|≤K(1×10-6R+2.5ΔR)
tenfourΩ, 10fiveΩ	±2×10-6	DC magnetic potential ≥ 1 ampere turn tenfourΩ, 10fiveWhen measuring Ω, use a high-voltage power supply
1001Ω ~10fiveΩ	|Δ|≤K(2×10-6R+2.5ΔR)

In the formula; |Δ | - Instrument error
R - The reading on the measuring disc is generally indicated at '10' to reduce measurement errors
Δ R - Minimum step value of the measuring disk
K - Proportional coefficient
3. Usage environment: Temperature: 20 ± 2 ℃, relative humidity ≤ 80%.
4. Power supply voltage: 220V ± 5%; When the power frequency is in the range of 49~50.5Hz, the error of the instrument should comply with the following
1) Low frequency noise ≤ 1 microampere turn
2) Zero drift ≤ 20 microamperes per 30 minutes
3) Power supply: AC 220V ± 5%, frequency 50 ± 0.5Hz. If this requirement cannot be met, FY93 AC stabilized power supply should be used.
5. Dimensions: 730 × 550 × 450mm
6. Weight: 85Kg