LS-450 Series Blue LED Pulsed Light Sources
LS-450 Series Blue LED Pulsed Light Sources
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Using Pulsed Mode
To operate the LS-450 in Pulsed mode, follow the steps below:
1. Connect one end of the DB-15 accessory connector to the back of the LS-450.
2. Connect the other end of the DB-15 accessory connector to the 15-pin connector or adapter on your
spectrometer. For more information, see the Pulsed Mode Connection Guide section later in this
document.
3. Move the switch on the back of the LS-450 to the “pulsed” setting to enable pulsed mode operation.
4. Configure Pulsed mode for your spectrometer. See the Pulsed Mode Connection Guide section later in
this document for more information.
5. Set the integration time in the OOIBase32 software so that a constant number of flashes occur for every
integration cycle. If you are using the S2000 spectrometer, you will need to set the integration time to
ensure a constant number of flashes per integration cycle. See the Pulsed Mode Connection Guide
section later in this document for a configuration table for the S2000 spectrometer.
See the OOIBase32 Spectrometer Operating Software Online Help System for more information on
setting the integration time.
Note: USB-based spectrometers automatically flash the lamp once per millisecond. Thus, there are
always a constant number of flashes regardless of the integration time configured.
Pulsed Mode Connection Guide
Follow the instructions below for your specific spectrometer to configure Pulsed mode on the LS-450:
S2000
1. Open the S2000 spectrometer housing and remove the spectrometer from the housing. Do not tamper
with the optical bench.
Note: If you have more than one channel in your system, you may have to disconnect the channels
from one another. The master spectrometer is always on the bottom of a multiple channel
system.
2. Locate Jumper Block 3 (labeled JP3) on the green circuit board. This jumper block consists of 10 pins,
which are labeled by rows (/16, /14, /12, /10, and 2).
3. Attach the jumper to the appropriate pins to configure the number of pulses per second for your A/D
converter. The table below illustrates the possible number of pulses per second for each A/D converter:
S2000 JP3 Pin Row
ADC2000-PCI Frequency (Hz)
ADC1000 Frequency (Hz)
/16 30.4
15.2
/14 120
60.8
/12 488
244.0
/10 1952
976.0
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Controlled by flash delay in software
(Continued)
