9
General Operations
The
internal reference system
(
reference detector
) of the photometer compensates for any drifts due to
power fluctuations or ambient temperature changes, providing a stable source of light for the blank (zero)
measurement and sample measurement.
LED light sources
offer superior performance compared to tungsten lamps. LEDs have a much higher luminous
efficiency, providing more light while using less power. They also produce little heat, which could otherwise
affect electronic stability. LEDs are available in a wide array of wavelengths, whereas tungsten lamps have
poor blue/violet light output.
Improved
optical filters
ensure greater wavelength accuracy and allow a brighter, stronger signal to be received.
The end result is higher measurement stability and less wavelength error.
A
focusing lens
collects all of the light that exits the cuvette, eliminating errors from cuvette imperfections and
scratches, reducing the need to index the cuvette.
5. GENERAL OPERATIONS
5.1. METER VALIDATION: CAL CHECK™
Validation of the
photometer
involves verifying the concentration of the certified CAL Check standards*.
The CAL Check screen guides users step‑by‑step through the validation process.
Warning
: Do not use any solutions or standards other than the Hanna Instruments® CAL Check standards.
For accurate validation, please perform it at room temperature, 18 to 25
°
C (64.5 to 77.0
°
F).
Note
: Protect the CAL Check cuvettes from direct sunlight by keeping them in the original packing. Store between
5 and 30
°
C (41 to 86
°
F). Do not freeze.
To perform a CAL Check:
1. Press the
key to enter the menu.
2. Use the functional keys to select
CAL Check
and press
Select
.
“
Not Available
“
message or date, time, and status of the last CAL Check will be displayed on the screen.
Note
: CAL Check is for the bandpass filter used by the selected method. Methods with the same bandpass filter
use the same CAL Check standards.