CALDUR® DEHA (Diethylhydroxylamine) test kit – Colorimetric
What is DEHA measured for?
DEHA (diethylhydroxylamine) is a highly effective oxygen binding agent that plays a central role in boiler water treatment and industrial steam generation. As an organic hydrazine substitute, DEHA binds dissolved oxygen in feed water and thus effectively prevents corrosion in steam boilers, pipelines and heat exchangers. Unlike hydrazine, DEHA is not carcinogenic and is therefore the preferred choice for modern boiler systems.
The typical dosage is between 0.1 and 0.5 mg/l DEHA, depending on the oxygen content of the feed water and the specific operating conditions. Regular monitoring of the DEHA concentration is essential to ensure adequate corrosion protection on the one hand and to avoid overdosing on the other. Too low DEHA values lead to insufficient corrosion protection, while too high concentrations are economically inefficient and can affect the pH value of the boiler water.
DEHA reacts with oxygen and forms acetic acid and nitrogen as reaction products. This reaction takes place at low temperatures and is accelerated at higher temperatures, which makes DEHA particularly suitable for low-pressure boilers and hot water systems.
How does the test set work?
The CALDUR® DEHA test set – Colorimetric works according to the proven ferrozine method. DEHA reduces trivalent iron ions (Fe³⁺) to divalent iron ions (Fe²⁺), which then form a violet color complex with the ferrozine reagent. The intensity of the coloration is directly proportional to the DEHA concentration in the water sample.
After adding two reagents to the water sample, a characteristic violet coloration develops within 5 minutes. The measured value is determined by direct color comparison with a 6-stage color chart provided. This colorimetric method enables fast and reliable on-site analysis without the need for expensive laboratory equipment.
Advantages of the CALDUR® test set
Quick analysis in just 5 minutes
Ideal for daily routine checks in boiler plants and steam generation systems
High precision in the relevant concentration range (0.05 – 1.0 mg/l)
Perfect for monitoring the optimum DEHA dosage in boiler water
100 provisions per set – economical in continuous use
Cost-efficient for regular inspections in power plants and industrial steam systems
Can be used colorimetrically – no additional devices required
Flexible for simple on-site tests directly on the boiler system
Easy handling without special equipment
No additional technology required – ideal for operating personnel
Robust, waterproof plastic housing with hinged lid
Safe transportation and protection of reagents – durable and reliable
Areas of application
Pond / lake
Groundwater / well water
Drinking / tap water
Aquaristics
Pool / Swimming pool
Industrial processing
Boiler water
Food preparation
Waste water treatment
Carrying out the measurement:
Fill water sample into test tube up to the 10 ml mark
Add 5 drops of reagent A and mix
Add 5 drops of reagent B and mix
Wait for 5 minutes reaction time
Perform color comparison with color chart
Tip for best results
The water sample should be brought to room temperature before the measurement.
If the boiler water is heavily colored, a blank value determination with distilled water is recommended.
Important notes
Take the sample as fresh as possible and analyze it immediately
Bring reagents to room temperature before use
Adhere exactly to the reaction time of 5 minutes
Avoid direct sunlight during the measurement
Rinse test tubes thoroughly with distilled water after use
Measuring range
Measuring level
Description
0.05 mg/l
Very low concentration (light violet)
0.1 mg/l
Low concentration (light violet)
0.25 mg/l
Optimum concentration (violet)
0.5 mg/l
Average concentration (violet)
0.75 mg/l
Elevated concentration (dark violet)
1.0 mg/l
High concentration (dark violet)
Read intermediate values:
If the color lies between two fields, you can form the mean value
(e.g. between 0.25 and 0.5 mg/l = approx. 0.35-0.4 mg/l).
Number of possible provisions
You can carry out 100 measurements with one CALDUR® DEHA test set.
This refers to the quantity of reagents contained.
Measuring accuracy and reproducibility
Readability: ± 1 color level Reproducibility: Very good if the application instructions are followed Interference: Other reducing agents such as Sulfite or hydrazine can influence the result. High concentrations of iron in the sample should be taken into account.
What to do if measured values are out of range?
Measured value > 1.0 mg/l
Dilution
Procedure
Calculation of the measured value
1:1
5 ml sample + 5 ml distilled water
Measured value × 2
1:4
2 ml sample + 8 ml distilled water
Measured value × 5
Measured value < 0.05 mg/l
Measured value is below the detection limit. This may indicate insufficient DEHA dosing – check the dosing system and increase the dosing quantity if necessary.
2 reagent bottles (reagent A, B) with detailed labeling
1 test tube with 10 ml scale
1 color card with 6 measuring levels
Detailed operating instructions (DE/EN)
Safety data sheets for all reagents
Robust hinged lid box (103 x 91 x 36 mm)
Reagent details
Reagent
Volume
Shelf life
Notes
Reagent A
15 ml
48 months (48M)
Ferrozine solution, shake before use
Reagent B
15 ml
48 months (48M)
Buffer solution, 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 away from direct sunlight.
We use cookies and analytics services (e.g. Google Analytics) to improve our website. Technically necessary services are always on. You can accept or decline optional services. More in the privacy policy