6517B-900-01 Rev. A / Jun 2008 Return to Section Topics 4-13
Model 6517B Electrometer User’s Manual Section 4: Measurement Options
Speed
SPEED sets the integration time of the A/D converter, the period of time the input signal is 
measured. The SPEED can be set for each measurement function. The integration time is 
specified in parameters based on a number of power line cycles (NPLC), where one PLC for 60Hz 
is 16.67msec and one PLC for 50Hz and 400Hz is 20msec.
In general, the fastest integration time (0.01 PLC) result
s in increased reading noise and less 
usable resolution, while the slowest integration time (10 PLC) provides the best common-mode 
and normal-mode rejection. In-between settings are a compromise between speed and noise.
Configuring speed
Each measurement function can have a unique integration time. Speed is set from the configure 
function menu structures. The procedure is summarized as follows:
 1. Press the CONFIG key and
 then the desired function key.
  2. Use the cursor keys to select SPEED and press ENTER to display the following speed 
options: 
NORMAL:  Sets the integration time to 1 PLC. 
FAST:  Sets the integration time to 0.01 PLC. 
MEDIUM:  Sets the integration time to 0.1 PLC. 
HIACCURACY:  Sets the integration time to 10 PLC. 
SET-SPEED-EXACTLY:  This options prompts you to enter a PLC value (0.01 to 10) 
SET-BY-RESOLUTION:  Automatically optimizes the integration time for the present 
resolution setting (see Section 4 of the Reference Manual).
  3. Use the menu items to configure speed. A menu item is selected by placing the cursor 
(blinking menu item) on it and pressing ENTER. Parameter values are changed using the 
cursor keys and the RANGE keys, and then pressing ENTER (see Menus for more 
information on navigating through the menu structure).
For more information, see Section 4 of the Reference Manual.
Resolution
All functions can operate from 3½ to 6½ digits of resolution. Each function can have a unique 
resolution setting.
Configuring resolution
Perform the following steps to set resolution for a measurement function:
 1. Press the CONFIG key and
 then the desired function key.
  2. Using the cursor keys, select RESOLUTION and press ENTER to display the following 
resolution options:
 a. 3.5 to 6.5d: Select one of these options to set the display resolution.
 b. AUTO: This option automatically optimizes the resolution for the present integration 
time (speed) setting (see Section 5 of the Reference Manual).
  3. Set resolution by placing the cursor on the menu option and pressing ENTER.
Filter
Filtering stabilizes noisy measurements. The Model 6517B uses a digital filter and a median filter. 
When a filter is enabled by pressing FILTER (FILT annunciator turns on), the selected filter for that 
measurement function is in effect. Pressing FILTER a second time disables the filter.
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