HP 3457A Service Manual page 47

The Integration Time can also be changed by pressing the NPLC/A key, entering the desired number directly, and pressing
the ENT/LAST ENTRY key.
3-16. Input Connections. For voltage measurements, the input voltage is connected to the INPUT HI and LO
Terminals. This is true for both Front and Rear Terminal operation. When using one of the optional
Plug-In assemblies, the input is connected to the HI and LO inputs of a particular channel.
3-17, Front/Rear Input Selection, The Input configurations are Front Terminals, Rear Terminals/Scanner
or Open. Only one input configuration (front, rear, scanner or open) can be selected at a time.
© To select Input configuration - Press the TERM / M configuration key. Use the ?/AUTO or |/HOLD
scroll key to display the desired input and press the ENT / LAST ENTRY key.
The input can also be changed by pressing the TERM/M key, entering the appropriate number, aud pressing the ENT/LAST
ENTRY key,
3-18. Resistance Measurements (Manual Operation)
3-19. Function Selection. The measurement function is selected by pressing the appropriate function key.
The resistance measurement functions available are 2-Wire Ohms and 4-Wire Ohms,
© To select 2-Wire resistance measurements - Press the OHM / OHMF function key.
© To select 4-Wire resistance measurements - Press the Blue SHIFT key then the OHM / OHMF key.
3-20. Range Selection. The Auto-Range feature automatically selects the appropriate range for the re:
tance being measured. The Auto-Range feature i s disabled by selecting Manual Ranging. There are 9 resis-
tance measurement
ranges available;
30 Ohms, 300 Ohms, 3 KOhms,
30 KOhms, 300 KOhms,
3 MOhms,
30 MOhms, 300 MOhms and 3 GOhms. The extended ohms ranges (300 MOhms and 3 GOhms) are available
only for 2-Wire resistance measurements. The default range is Auto-Range.
© To select Manual Ranging and the next higher range - Press the /AUTO scroll key.
© To select Manual Ranging and the next lower range - Press the }/HOLD scroll key.
© To return to Auto-Ranging - Press the Blue SHIFT key then the }/AUTO scroll key.
3-21. Measurement
Resolution. Measurement Resolution
is changed by selecting the number of digits dis-
played. You can choose
a display of 3 1/2, 4 1/2. 5 1/2 or 6 1/2 digits. The 1/2 digit refers to the most sig-