Caldur® Nitrate – Photometric
Determination of nitrate in water using a photometer (0.5-50 mg/l NO₃-)
Private customers can also find our range in our partner store Ampha-Analyse.
Reagent for Caldur® Nitrate – Photometric:
See also:
CALDUR® Nitrate Test Set – Photometric
What is nitrate measured for?
Nitrate (NO₃-) is one of the most important water quality parameters. It enters the water via fertilizers, wastewater and natural decomposition processes. The drinking water limit value is 50 mg/l NO₃- (Drinking Water Ordinance).
Elevated nitrate levels indicate agricultural pollution or inadequate wastewater treatment. In infant formula, nitrate can be reduced to dangerous nitrite, which is why monitoring is particularly important.
In industrial water treatment, in cooling circuits and in wastewater treatment, nitrate measurement is used for process control and compliance with discharge limits.
How does the test set work?
The CALDUR® Nitrate Test Set – Photometric is based on the NED method (naphthylethylenediamine). After adding two reagents to the water sample, a characteristic coloration develops within 6 minutes, the concentration of which is precisely determined with the WINLAB Data Line photometer.
Advantages of the CALDUR® test set
- Wide measuring range 0.5 – 50 mg/l NO₃-
Covers the entire practical range including drinking water limit value
- 200 provisions per set
Cost-efficient for continuous use
- High precision due to photometric evaluation
Objective, reproducible measurement results with the WINLAB Data Line
- Proven NED method
Reliable and selective detection method
Areas of application
Carrying out the measurement:
- Fill the round cuvette with sample up to the 10 ml mark
- Add 5 drops of reagent A and mix
- Add 5 drops of reagent B and mix
- Wait for 6 minutes reaction time
- Insert the cuvette into the WINLAB Data Line photometer
- Start measurement – result is displayed directly in mg/l NO₃-
Tip for best results
The sample should be clear and free of suspended solids. Filter truebe samples before measurement. Sample temperature between 15 and 25°C ensures optimum results.
Important notes
- Adhere exactly to the reaction time of 6 minutes
- Avoid direct sunlight during the measurement
- Wipe the cuvette with a lint-free cloth before measuring
- Thoroughly rinse the test tube with the sample before each measurement
- Neutralize high chlorine concentrations before measuring
- Requires WINLAB Data Line photometer (Art. 37-000100)
Measuring range
| Property | Value |
|---|---|
| Measuring range | 0.5 to 50 mg/l NO₃- |
| Resolution | 0.1 mg/l |
| Method | NED method, photometric evaluation |
In contrast to the colorimetric method (color chart), the photometer provides exact numerical values with a higher resolution. Intermediate values are calculated automatically – ideal for documentation and quality assurance.
Number of possible destinations
You can carry out 200 measurements with one CALDUR® Nitrate Photometric Test Set.
This refers to the quantity of reagents contained.
Measuring accuracy and reproducibility
Resolution: 0.1 mg/l
Reproducibility: Very good if the application instructions are followed
Interference: Strongly oxidizing or reducing substances can influence the result. High chlorine concentrations (> 5 mg/l) should be neutralized before the measurement.
What to do if measured values are out of range?
Measured value > 50 mg/l
| Verduction | Execution | Calculation of the measured value |
|---|---|---|
| 1:1 | 5 ml sample + 5 ml nitrate-free water | Measured value × 2 |
| 1:4 | 2 ml sample + 8 ml nitrate-free water | Measured value × 5 |
Measured value < 0.5 mg/l
Measured value is below the detection limit. For more sensitive measurements, please contact our technical support.
Specifications at a glance
| Property | Value |
|---|---|
| Parameters | Nitrate (NO₃-) |
| Item number | 31-073342 |
| Method | Photometric (NED) |
| Measuring principle | Photometric evaluation with WINLAB Data Line |
| Measuring range | 0.5 to 50 mg/l NO₃- |
| Resolution | 0.1 mg/l |
| Duration of analysis | 6 minutes |
| Number of provisions | 200 |
| Number of reagents | 2 |
| Packaging | Plastic bag |
| Scope of delivery |
|---|
| 2 reagent bottles (reagent A, reagent B) with detailed labeling |
| 1 round cuvette (10 ml) |
| Detailed operating instructions (DE/EN) |
| Safety data sheets for all reagents |
| Resealable plastic bag |
Reagent details
| Reagent | Volume | Shelf life | Notes |
|---|---|---|---|
| Reagent A (NED 1) | 30 ml | 24 months (24M) | NED reagent, shake before use |
| Reagent B (reducing agent) | 30 ml | 24 months (24M) | Shake before use |
Shelf life: The shelf life starts from the date of manufacture (printed on the bottle).
After opening, the reagents should be used within 12 months.
Store the test kit in a dry, cool place (10-25°C) and protected from direct sunlight.
Required accessories
The photometer is not included in the test set and is available separately.
Additional information
| Packaging | Plastic bag, Refill pack |
|---|
Flyer
Operating instructions
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