Powering the Optimus/Optimus+

Modified on Tue, 28 Nov 2023 at 10:22 AM

Optimus/Optimus+ sound level meters can be powered by a number of different methods.

1. Battery power

An Optimus/Optimus+ uses standard 4 x AA 1.5v batteries to provide 6v of power and is supplied with alkaline primary cells that will give approximately 12 hours operation. It is recommended that only non-rechargeable AA batteries are used for optimum performance.

Non-rechargeable lithium type AA batteries can also be used and these can often provide 18-20 hours operation. They are much more expensive than alkaline AA cells.

*AA batteries are also known as MN1500, LR6, MIGNON or STILO.

The operating life available from other battery types may differ. Lower-quality batteries will provide less power and that can result in significantly shorter operating times.

Cirrus Research plc has no control over the quality of the batteries that are used and therefore the operating times given in this article are typical and are stated for a new set of Varta Industrial AA Alkaline batteries, as supplied with new instruments. 

The Optimus/Optimus+ instruments will show the level of the internal batteries with an indicator in the top right-hand corner of the screen.

When the batteries are new, the indicator will be green and will show all four segments filled. As the batteries are used, the power available will reduce and the battery level indicator will change accordingly. As the batteries get to the end of their life and the last segment is filled, the colour will change from green to red. It is recommended that the batteries are changed at this point.

If the batteries are not changed, the available power will fall to a point where the battery indicator will start to flash. You must stop any measurements and replace the batteries to ensure that the instrument continues to operate as intended.

We would recommend that you keep a spare set of batteries in the instruments carrying case so that you can change the batteries when needed. If the instrument is switched on and there is insufficient power in the batteries to allow the unit to start, the display will flash quickly but the instrument will not start. Please change the batteries immediately to allow the instrument to be used. 

2. Powering the Optimus from an external supply

The recommended method of powering an Optimus/Optimus+ from an external power supply is to use the Multi-IO connector and a 12v power supply.

Powering the Optimus from a USB power supply is recommended for short term use only. It is not recommended that the Optimus is powered for long periods by the USB connector.

USB power supplies often produce high levels of electrical noise and whilst the Optimus has been designed to reject external electrical noise as much as possible, it may still be affected by any noise produced by the power supply.

Please note that Cirrus Research plc accepts no responsibility for the use of any cable, power supply or accessory not supplied by us. Use of any such may invalidate the warranty and may cause damage to your instrument.

In particular, this applies to the use of USB power supplies, such as those used to charge mobile phones.

2.1 External power via the Multi-IO

The Optimus/Optimus+ can be powered via the multi-pin connector on the bottom of the instrument. Power can be connected using the following cables:

  • ZL:171 Optimus DC Power In Cable with 2.1mm Power Socket
  • ZL:176 Optimus 12v Battery pack cable 2m to tinned ends with inline fuse

2.2 Short term external power via the USB connector

The Optimus/Optimus+ instrument can also be powered from an external source, such as a USB connection to a PC or via a USB power supply.

Please note that if external power is provided by the USB connection, this is a 5v supply and is lower than the 6v provided by the internal batteries.

The Optimus/Optimus+ will use the highest available power source and may take power from the internal batteries in until they fall below the 5v available from the USB connection. When an external power supply is connected, the display will show a USB symbol next to the Battery Level Indicator. 

Please note that Cirrus Research plc accepts no responsibility for the use of any cable, power supply or accessory not supplied by us. Use of any such may invalidate the warranty and may cause damage to your instrument.

Last updated: 25th November 2015

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