一：概述

NAGKT-I型數字式高電氣儀表校驗試驗臺（也叫做：數字式多用表校驗儀、三表校驗儀）是一種LED五位數字式交、直流標準電壓、電流發生器，用于校驗數字式電表、各種指針式電表及直流0.2級，交流0.5級以下各類表頭。本儀器電壓輸出五檔（0~1000V）；電流輸出六檔（0~10A）；可以選配：中值電阻2×11檔(0Ω~24MΩ)；交流頻率50Hz,60Hz,400Hz（數字合成，按鍵選擇）。以上項目及量程變換均通過內部開關轉換。采用新的16位A/D轉換芯片，轉換速度和得到了大幅度提高；AC/DC采用真有效值轉換芯片，保證了交流輸出的；整機線性度好。采用了新型的復合大功率放大器，輸出功率強大，可靠性高，失真度小。輸出調節采用進口電位器，壽命長，調節細度高。整機采用“閉環控制”，輸出穩定度高。電壓短路、電流開路自動保護，完全符合新三表鑒定規程。

二、工作原理：

本儀器有數字合成正弦波發生器單元、功放單元、電源及保護單元、量程單元、A/D單元、顯示單元、鍵盤單元及標準電阻器等組成。

三、技術性能：

2.1性能參數：

2.2：交流失真度：不大于1% 。

2.3：直流紋波系數：不大于0.5%；電流10A不大于3% 。

2.4：穩定性：儀器預熱一小時后，1分鐘內輸出漂移應小于基本量程滿度的±0.05%，作精密測量時需預熱2小時。

2.5：外型尺寸：480×340×134（mm）。

2.6：重量：10Kg。

NAGKT-I electrical instrument test-bed

I. Overview

NAGKT-I digital electrical instrument calibration test bench (also called: digital multimeter calibrator, 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 of 0.5 below the various types of table head. (0 ~ 12MΩ); AC frequency of 50Hz, 60Hz, 400Hz (digital synthesis, the output voltage of the three-phase voltage range of 0 ~ Button to select). The above items and range conversion are converted by internal switches. Using the latest 16-bit A / D converter chip, conversion speed and accuracy has been greatly improved; AC / DC converter with true RMS value to ensure the accuracy of AC output; linearity is good. Using a new type of composite high-power amplifier, the output power of strong, high reliability, low distortion. Output adjustment using imported potentiometer, long life, high fineness regulation. The machine adopts "closed-loop control", the output stability is high. Voltage short-circuit, open current automatic protection, in full compliance with the new three table identification procedures.

Second, the working principle:

The instrument has a digital synthesis sine wave generator unit, power amplifier unit, power and protection unit, 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 be less than the full range of the 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.