型号 AR-841 AR-851 Measuring Range 0.5～15m 0.5～15m(single Unit) 测量范围 1～60m(Double Unit) Accuracy ±0.5% ±1.5%(single Unit) 测量精确度 ±2%(Double Unit) Measure In Imperial/Metric √ √ 公英制转换 Operation Condition 0～30℃ 0～30℃ 工作环境 30-70%RH 30-70%RH Laser Pointer Aiming Selection √ √ 激光定位 Low Battery Indication √ √ 低电显示功能 Computer Area And Volume √ √ 计算面积和体积 Sum Of Length √ √ 计算长度累加 Auto/Manual Shut-off √ √ 自动/手动关机 LCD Backlight √ √ LCD 背光显示 response Time 2s 2s 响应时间 Measureing Benchmark Setup √ √ 测量基准设置 Single Or Double Unit Measure Selection _____ √ 单机和双机测试选择开关 WorkFrequency 40khz 40khz(single Unit) 工作频率 20khz(Double Unit) Key Sound,Beeps For Wrong Reading √ √ And Reading Confirmation 按键声提示,出错声音提示 以及确认声音提示