Guide to getting started

Guide to getting started

The Open Colorimeter has the following features:

  • On/Off switch: An on-off switch will save battery power when not in use
  • Micro USB Port: You can power from the Micro USB port and it will also charge up the battery
  • Blank button: Use this with a blank reference (no signal) to set the measurement background before sample measurements. A cuvette with distilled water is commonly used as the blank reference
  • Menu button: Use this to switch to the menu screen
  • Menu navigation cluster: Use these buttons to navigate ⇧⇩⇨ through the Menu
  • Gain and Integration time: Sets the gain and integration time of the internal amplifiers for the photodiode channels allowing the user to control the sensitivity of the device. These are only active in the "Raw Sensor" measurement screen.

Instructions and Menu Navigation

You can set into a few different mode. Absorbance, Transmittance or a concentration. Use the menu navigations to select the mode of choice. Make sure you're using the correct LED. If not read instructions to switch it out below

  1. Switch on the colorimeter
  2. An intro splashscreen appears followed by the absorbance screen
  3. Press the Top Left button to enter the Menu
  4. Use the cluster of 4 buttons on the lefthandside to navigate ⇧⇩ the menu
  5. To select a Mode (e.g. Transmission) press the right ⇨ button in the cluster
  6. Press the Top Left button to go back to the Menu at anytime

Blanking the colorimeter

Before taking a measurement, you need to blank (aka 'zero' or 'calibrate') the colorimeter. This sets the measurement background against which your sample is compared. A cuvette with distilled water is commonly used as the blank reference. It should be a sample with no 'signal' present

  1. Switch on the colorimeter and place the blank sample in the cuvetter holder. Place the black light-blocking cover over the cuvette holder
  2. Press the Top Right Blank button. You should see a flashing "Blanking" line on the screen
  3. Once the blanking has finished, put your sample in and record the absorbance, transmittance or concentration value, whichever mode you are using

Changing LED wavelengths

The instrument currently operates with one LED wavelength at a time. However the user can easily swap out the LED board without having to disassemble or take apart the colorimeter.



The cuvette holder inner dimension is 12.65 mm x 12.65 mm. We include a pack of 6 BrandTech macro and semi-macro cuvettes (3 of each). BrandTech cuvettes are approx. 12.47 mm x 12.47 mm. Other cuvettes we have checked are the BrandTech Ultramicro UV cuvettes (for 70 µL sample sizes). You can use any cuvette of choice as long as the dimensions are no greater than 12.5 mm x 12.5 mm.

Batteries and recharging

The unit comes with a 3.7V 420 mAh lithium ion battery and a USB A to micro B cable. When you first turn on the colorimeter you will see a battery display that tells you the charge on the battery. When the battery is running low, plug in the micro USB cable to charge. You can change out the battery in the colorimeter to a longer-lasting one, for example: 3.7V 2000 mAh. When choosing to upgrade the battery, just make sure it has a 2-pin JST-PH connector.