The Vaihaila Scientific Model 2500 AC-DC Current Calibrator is a complete wide range voltage-to-current convertor. This instrument will convert a precision input voltage to a proportional output current. If the input voltage is DC, the output current w ill have the polarity of the input voltage. If an AC signal is applied to the input terminals, the output current will have the frequency and phase of the applied input voltage. Seven current ranges, from one microampere to one ampere are selectable with the front panel range switch. The legends above each push-button indicate the current produced at the output terminals when one volt is ap­plied to the input terminals. 1-3 The Model 2500 AC-DC Current Calibrator is housed in an extra heavy-duty aluminum case, ideally suited to the most rugged requirements.