Cirrus Optimus Green Series, Instrument Hanbook

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Optimus sound level meter - instrument handbook
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The output is unweighted, i.e. Z-weighted.
AC output cables
The AC output should be used with a ZL:174, ZL:177 or ZL:185 cable.
These cables are available from Cirrus Research plc or your local distributor. Do not
use any other cable the Optimus. This may damage the instrument and invalidate
your warranty.
8.5.2 DC output
The DC output is provided on the 18-pin Multi-IO socket at the bottom of the
instrument. The output is set to 25 mV/db with LAF updated 16 times per second.
DC output cables
The DC output is available using a ZL:174 output cable.
This cable is available from Cirrus Research plc or your local distributor. Do not use
any other cable with the Optimus. This may damage the instrument and invalidate
your warranty.
8.5.3 Threshold triggered output
An external discrete available on the 18 Pin Multi-IO socket at the bottom of the
instrument can be triggered when an audio trigger event is detected. This trigger
will toggle the output from 0 to 3.3V and can be used to trigger external devices, for
example a camera or noise warning sign.
The trigger output can be enabled in NoiseTools as an event when an audio trigger
occurs.
The trigger output is available on the 18 pin Multi-IO Cable ZL:183 wires (black-return,
brown – trigger).
The trigger output is a TTL output. To avoid damage to the instrument do not apply
any external voltage to this signal and limit current drawn to less than 2mA.
8.5.4 Cables
The Optimus sound level meters can be used with a range of cables. The standard
cables are listed below.
Microphone extension cables
ZL:205 - 5 m microphone extension cable
ZL:210 - 10 m microphone extension cable
ZL:225 - 25 m microphone extension cable