Keithley 6485 User Manual

6-4 Buffer Model 6485 Picoammeter Instruction Manual
Buffer timestamps
Use the TSTAMP: menu item to change the timestamp format. To access the menu:
1. Press MENU.
2. Scroll to the TSTAMP: menu item using RANGE keys  and .
3. Press ENTER.
4. Using RANGE keys  and , select desired setting. Available options are ABS
(absolute) or DELT (delta).
5. ABS: each timestamp is referenced to the first reading stored in the buffer. The first
reading always has a timestamp of 0000000.0000.
6. DELT: each timestamp provides the time between the readings.
Buffer statistics
• MIN and MAX provides the minimum and maximum readings stored in the buffer.
It also indicates the buffer location of these readings.
• The PK-PK (peak-to-peak) value is the difference between the maximum and
minimum readings stored in the buffer:
PK-PK = MAX - MIN
• Average is the mean of the buffer readings. Mean is calculated as follows:
Where: X
i
is a stored reading
n is the number of stored readings
• The STD DEV value is the standard deviation of the buffered readings. Standard
deviation is calculated as follows:
Where: X
i
is a stored reading
n is the number of stored readings
Avg is the mean of the buffer readings.
y
n
Σ
X
i
n
-----
i=1
=
y
n
Σ
Avg X
i
–()
2
i1=
n1–
------------------------------------=

Keithley 6485 Specifications

General

Brand	Keithley
Model	6485
Category	Measuring Instruments
Language	English