YJ139a type calibratorDetailed product description：

1. Purpose:
YJ139a calibrator is a new type of digital direct reading DC voltage and current calibrator with the function of measuring and outputting DC voltage. YJ139a also has the function of measuring and outputting DC current, which can be used to detect thermocouples and transmitters, and can also be used as a secondary instrument signal to directly calibrate various industrial automation instrument transmitters and dynamic coil temperature instruments with thermocouple temperature measurement. The instrument has a novel design, easy operation, low power consumption, and comes with a working power battery box for easy portability. It can also be connected to an external DC power source, making it suitable for use in production sites and laboratories.

Technical indicators:
2. Main technical indicators:
a. Range: YJ139:1 μ V~19.999V (measurement)
1 μ V to 1.9999V (output)
YJ139a：1μV～1.9999V; 0.1μA～19.999mA
b. Accuracy: ± 0.05

c. Main parameters
Products YJ139, YJ139a

Function measurement output measurement output

Range 1 μ V~19.999mV 1 μ V~19.999mV
10μV～0.19999V　　10μV～0.19999V
100μV～1.9999V　　100μV～1.9999V
1mV～19.999V　　　1μA～19.999mA
0.1μA～1.9999mA

Grade index () 0.05 0.05
d. Power supply voltage and battery type: 8 No. 5 batteries or 2 external 6V DC power supplies
e. Dimensions: YJ139:258 × 134 × 67 (mm)
YJ139a：140 × 256 × 67(mm)
f. Quality: 1kg