DC Ammeter with Hall Sensor LED Digital Display 50A High Accuracy Current Gauge for Vehicles Item Type: Digital Ammeter Material: ABS Current Range: 50A Test Range (V):+/-0.0-50A, Resolution (A): 0.1A Display Mode: 0.52in LED, Red External Dimension: Approx. 54 x 30 x 21mm / 2.13 x 1.18 x 0.83in Installation Opening: Approx. 47.2 x 27.3mm / 1.86 x 1.07in Measurement Rate: ≥ 500mS/Time Measurement Accuracy: 1% (± 2 Words) Power Supply End Lead: Approx. 150mm / 5.91in Transformer Lead: Approx.150mm / 5.91in Working Temperature: - 10-+65℃ Working Humidity: 10-80% (No Condensation) Working Pressure: 80-106kPa Exposure To The Sun: Direct exposure is not allowed Calibration Method: The relative error between the instrument and the instrument, or the error caused by the aging of components or environmental temperature change after long term use, can be calibrated by the following methods. In order to obtain more accurate measurement, it is recommended to preheat for more than 5 minutes before calibration. Current Calibration: Under the condition that there is no current flowing, use a slotted screwdriver to adjust the zero potentiometer behind the mutual inductor until the decimal point of the ammeter flashes quickly as the best point; Constant light or no light indicates that the zero point is positive, and slow flashing indicates that the zero point is negative. Then, under the condition of loading half of the actual current value to be measured, adjust the amplitude modulation potentiometer on the side of the transformer until it is consistent with the standard table. If the test accuracy is very high, the above two steps can be repeated to obtain higher accuracy.