Doric Instruments 1000 Pro Series Digital Panel meters are suitable User Manual

Page 22

1000-FREQ

Frequency

Equipment Required:

1. Precision AC voltage source with a resolution to 0.1mV and

an accuracy of ±0.1%

2. Interconnecting copper wire from the AC source to the

indicator.

3. Trimmer adjusting tool.

STEP 1.

Disconnect power from the unit and using copper

connecting leads, connect the output of the AC Voltage source to
terminals 5 and 6 of the indicator according to the chart on page 5.

STEP 2.

Remove the front panel lens and reconnect power and

allow for a 5-minute warm-up.

STEP 3.

Input 100.0 mV at 60 Hz from the AC voltage source

and adjust the ZERO pot for a display reading of 60±1count.

STEP 4.

Input 100.0 mV @400 Hz from the AC voltage source

and adjust the SPAN pot for a display reading of 400±1count.

STEP 5.

Repeat steps

2 and

3 until no further adjustment is

needed.