Hach Portable Spectrophotometer DR 2800 User Manual page 44

Standard Operations
Options
Store Off/On
% Trans/Conc/Abs
Send Data icon /
Send Data
Timer icon
Dilution Factor Off/On
Standard Addition
Standard Adjust
Chemical Form
Reagent Blank
Save as User Program
Recall Data
Instrument Setup
44
Table 4 Stored programs options (continued)
Description
With the Store On setting, all measurement data are stored automatically. With the Store Off
setting, no measurement data are stored.
To switch to % transmittance, concentration or absorbance readings
To send Data to a printer, computer or USB memory stick (Type A)
This functions as a stopwatch. It helps to ensure that the steps of an analysis are correctly timed
(e.g. reaction times, wait times, etc., can be exactly specified). When the specified time has
elapsed, an acoustic signal is emitted. The use of the timer has no influence on the measurement
program.
A corrective dilution factor can be entered in order to take account of certain properties.
The number entered at the dilution factor prompt will be multiplied by the result to compensate for
the adjustment. For example, if the sample has been diluted by a factor of 2, enter 2. The default
setting of the dilution factor is turned off.
Note: When a dilution is in effect, the dilution icon will appear on the display.
This enables the accuracy of the measurements to be checked. The (working) procedure for a
test parameter contains a detailed explanation of how to use this function.
The (working) procedure for a test parameter indicates whether a standard adjustment is
necessary and, if so, how to proceed.
Some of the stored tests/methods allow to select the chemical form and the measuring range.
Some of the stored tests/methods include the "Reagent Blank" function. This enables the reagent
blank value to be added to or subtracted from, the subsequent readings. The reagent blank value
shifts the calibration curve along the y-axis, without changing the shape or gradient of the curve.
The effect corresponds to a y-axis intercept of the calibration straight line. This is made clear by
the following equation: Concentration = [(Conc. factor) * Abs] – (reagent blank value).
To store the selected parameters as a User Program, see
Call up saved measurement data or time courses, see
Basic data of the instrument, see
section 6.1 on page
section 5.3 on page
section 5.2 on page 27.
61.
37.