BC5/2 standard battery

Portable saturated standard batteries have a wide range of applications, suitable for electrical measurement rooms in industrial and mining areas, schools, research institutions, etc., and used as electromotive force measuring tools in laboratories. Potentiometer, digital voltmeter, automatic recording instrument. Hydrogen ion concentration meters and other options are available for selectionBCUsed in conjunction with standard batteries,BCThe internal of the standard battery has been improved to withstand tilting, inversion, and shaking without damage, making it easy to carry and transport.

Ⅱ.Technical Parameter

1. Stability level:0.005Grade.

2. Working conditions: ambient temperature+10°～+40℃, relative humidity ＜80%

3. The temperature is+20At ℃, the actual value of the standard battery electromotive force is1.01850~1.01870V.

4. At a temperature of+20Under the condition of ℃, the allowable variation of electromotive force value for standard batteries during the inspection period is ≤25μV.

5. At a temperature of+20Under the condition of ℃, the allowable variation of electromotive force value of a standard battery within one year is ≤50μV.

6. Environmental temperature deviation of standard batteries within the working temperature range20The actual value of its electromotive force at ℃ is determined by the following formula:

Et=E20- [α]（t-20）+β（t-20）2-r（t-20）3]*10-6V

In the formula:Et——The temperature istThe electromotive force value of a standard battery at ℃;

E20- Temperature at20The electromotive force value of a standard battery at ℃;

α=40.6；

β=0.95；

γ=0.01.

7. The allowable deviation of the alpha value between the measured value of the standard battery electromotive force and the value calculated according to the above formula is ＜ ±5×10-6V/℃.

8. Allow high current (one minute) through standard batteries1μA.

9. The internal resistance of the standard battery at the factory is less than1000Ω（+20℃).

10. The insulation resistance of the standard battery circuit to its casing is less than or equal to5000MΩ (test voltage is2500VThe ambient temperature is+15°~+25℃, relative humidity<80%）.

characteristic:Standard batteries are generally used for electromotive force verification, as they have stable electromotive force and a small temperature coefficient (temperature changes have little effect on electromotive force). The cadmium mercury battery invented by Weston is often used as a standard battery, which has a high degree of reversibility. Weston batteries are mostly saturated, with two types: H-tube and single tube. There is also a standard battery that is dry, in which the solution is in the form of a paste and unsaturated, so it is also known asPaste like unsaturated batteryThis type of battery has slightly lower accuracy and can generally be exempted from temperature correction. It is often installed in portable devicesPotential difference meteramong

use:

Standard batteries are not allowed to shake or be placed on the side, and should avoid severe vibration or inversion. Otherwise, it will cause irreversible changes and even damage.

Standard batteries cannot be used as primary batteries for outputting electrical power, and generally cannot exceed 1 microampere when in use. Excessive current will cause irreversible changes in the electromotive force.

The temperature coefficient of the electromotive force of a saturated standard battery is relatively large, about 4 × 10 ^ 3^-5/In general, it should be ensured that the temperature during calibration and use is consistent. If there is a difference between the two, interpolation formula needs to be used for correction. In precision measurement, in order to ensure the stability of the electromotive force value of the standard battery, it is necessary to place the standard battery in an oil tank with automatic temperature control. The temperature change range of the oil tank is about ± 0.01 Kelvin, and high-quality oil tanks can reach ± 0.001 Kelvin. Since the 1970s, air constant temperature baths controlled by electronic devices have been developed, which have high temperature stability and can be made portable, thus being widely used.

BC5/2 standard battery