一：概述

NAGKT-I型数字式电气仪表校验试验台（也叫做：数字式多用表校验仪、三表校验仪）是一种LED五位数字式交、直流标准电压、电流发生器，用于校验数字式电表、各种指针式电表及直流0.2级，交流0.5级以下各类表头。本仪器电压输出五档（0~1000V）；电流输出六档（0~10A）；可以选配：中值电阻2×11档(0Ω~24MΩ)；交流频率50Hz,60Hz,400Hz（数字合成，按键选择）。以上项目及量程变换均通过内部开关转换。采用**的16位A/D转换芯片，转换速度和精度得到了大幅度提高；AC/DC采用真有效值转换芯片，保证了交流输出的精度；整机线性度好。采用了新型的复合大功率放大器，输出功率强大，可靠性高，失真度小。输出调节采用进口电位器，寿命长，调节细度高。整机采用“闭环控制”，输出稳定度高。电压短路、电流开路自动保护，完全符合新三表鉴定规程。

二、工作原理：

本仪器有数字合成正弦波发生器单元、功放单元、电源及保护单元、量程单元、A/D单元、显示单元、键盘单元及标准电阻器等组成。

三、技术性能：

2.1性能参数：

2.2：交流失真度：不大于1%。

2.3：直流纹波系数：不大于0.5%；电流10A不大于3%。

2.4：稳定性：仪器预热一小时后，1分钟内输出漂移应小于基本量程满度的±0.05%，作精密测量时需预热2小时。

2.5：外型尺寸：480×340×134（mm）。

2.6：重量：10Kg。

NACKT-I electrical instrument test-bed

I. Overview

NAGKT-I digital electrical instrument calibration test bench (also called:digitalmultimetercalibrator,three-table calibrator) is a five-digit LED AC, DC standard voltage, current generator for Calibration digital meters, a variety of hands-meter and DC 0.2, the exchange of0.5below thevarious typesof table head. (0 ~ 12MΩ); AC frequency of 50Hz, 60Hz, 400Hz (digital synthesis, the output voltage of the three-phase voltage range of 0 ~ Button toselect). Theabove itemsand range conversion areconverted by internal switches. Using the latest 16-bit A / D converter chip, conversion speed and accuracy has been greatly improved; AC / DCconverter with trueRMS value toensure the accuracy of ACoutput;整机linearity is good. Using a new type of composite high-power amplifier, the output power of strong, highreliability, lowdistortion. Output adjustment using importedpotentiometer, long life,high fineness regulation. The machine adopts "closed-loop control", the output stability is high. Voltageshort-circuit, opencurrent automatic protection, in full compliancewith the new three tableidentification procedures.

Second, the working principle:

The instrument has a digital synthesis sine wave generator unit, power amplifier unit,powerand protectionunit,range unit, A / D unit, display unit, keyboard unit and standard resistors and other components.

Third, the technical performance:

2.1 Performance parameters:

2.2: AC distortion: less than 1%.

2.3: DC ripple factor: not more than 0.5%; current 10A not more than 3%.

2.4: Stability: the instrument warm-up after one hour, 1 minute output drift should belessthan the full rangeofthe basic range of ±0.05%, for precision measurements need to warm up 2 hours.

2.5: Overall dimensions: 480×340×134(mm).

2.6: Weight: 10Kg.