User manual

2638A
Users Manual
3-32
Channel Delay
A channel delay is a measurement time delay that can be individually assigned to each
channel to delay the measurement. Channel delays can be used for various applications,
but they are most useful in applications where the source impedance or circuit
capacitance is high. Use of a channel delay in these applications allow the input signal to
settle before a measurement is made. This provides better measurement accuracy.
When a channel delay is set, the Product inserts the delay after the channel relays switch
and waits until the channel delay time runs out before it measures the channel. Channel
delays are set in seconds and the default setting is 0 seconds.
To set a channel delay:
1. Push
.
2. Push  or  to highlight a channel then push .
3. Push  to open the Channel Options menu.
4. Select
Channel Delay then push .
5. Set the custom channel delay. The delay can be manually set in 1 millisecond
increments from 1 millisecond to 600 seconds.
Rate of Change
Rate of Change is a statistical calculation that shows the user how much a measurement
value has changed over a period of time. The Rate of Change is viewed in the
statistics/graphing area in the Scan Menu. The Rate of Change setting in the Channel
Options menu sets the scaling to per second (/s) or per minute (/min).
Note
Per minute (/min) is the default scaling selection unless otherwise changed.
To determine the rate of change, the Product compares two readings of a channel
sampled at different times. First, the product computes the difference between the two
readings and then divides it by the time difference between the samples in seconds. The
result is then multiplied by the time base in seconds (60 for per minute) to determine the
Rate of Change.
Note
If a channel is sampled more frequently than once every 10 seconds, two
readings about 10 seconds apart are selected. If the interval between
readings is 10 seconds or longer, the latest two readings are used.
To change the Rate of Change time base for a channel:
1. Push
.
2. Push  or  to highlight a channel then push .
3. Push  to open the Channel Options menu.
4. Select
Rate of Change then push .
5. Select per second or per minute then push .