http://www.jinhuayb.com/xiaoyan/index.html 
 JH-ZJF-7-based automated meter field simulator (DMM simulation instrument) is a set of digital DC voltage, millivolt, current source and digital multimeter functions in one high-precision, high resolution, high reliability and anti-drop performance with integrated digital hand-held calibrator. Instrument of high character with a large 22mm LCD display, clear reading, but also has the EL backlight instrument in order to light the dark places in the reading. Instrument for the AC and DC power, more convenient to use. 

 Instrument signal output and mA, mV measurement is mainly the implementation of field instrumentation for the industrial automation field calibration, maintenance needs and design. The instrument also has the general function of the multimeter is a field instrument engineering, computer maintenance personnel distributed control system, instrument an ideal tool for installation work. It different from the common electrical multimeter and signal source, the meter is working instrument. 

 VLSI circuit design to machine double integral A / D converter as its core, with the signal output and test functions, its technical performance in line with power II, III, Automatic Electric Meter calibration standards, the working environment in line with GB6587.1- 86 "master environmental testing electronic measuring instruments" in the II group of the relevant provisions of the instrument. 

 Functions and features of a 

 * 4 1 / 2 LCD display, digit height 22mm. 

 * Over Range Display "1", the maximum display value of 19999. 

 * 24V.DC (30mA.MAX) power output, can be used as two-wire instrument 24V.DC working power source. 

 * A 0-10V ,0-100mV ,0-20mV ,0-20mA and 0-22mA DC signal source can be simulated on-site verification of various II, III-type instrument such as the output signal. 

 * A 0 ~ 20KHz frequency output. 

 * There 200mV, 2V, 20V, 200V, 700V DC voltage signal measurement files. 

 * There 20mA, 100mA DC current signal measurement files. 

 * A 2V, 20V, 200V, 700V AC voltage signal measurement files. 

 * There 20mA, 100mA AC current measurement files. 

 * There 200Ω, 2KΩ, 20KΩ, 200KΩ, 2MΩ, 20MΩ resistance measurement files. 

 * A diode drop and the line through sold out. 

 * There 20KHz frequency measurement files.