STEP SYSTEMS Nitrachek 404 User manual

Operation Manual
Nitrachek 404
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Nitrachek 404 measures nitrate in
plant soil water
The test-strips are pre-tested.
A sticker on the container shows the lot number that must be
displayed on Nitrachek, before starting measuring.
Range = 5 à 500 mg/l NO3 (+/- 10 %)
Accuracy is higher in the middle of the range (50 – 250 mg/l)
A plastic checker allows test the meter.
A standard solution, delivered with the strips, allows training
and testing the whole procedure.
Dipping time = 2 s .
Get rid of a standard solution tube after 10 tests.
Presentation

Nitrachek description
Sliding switch to swtich off the beeper
9 V battery compartment
2 diodes and miror
Hatch, finger, strip carrier

Battery
Hatch must be closed when battery is changed
Remove the battery, if the meter is not to be used during
several months.
If battery is changed within 30 seconds , datas are kept in
memory.
A battery icon is displayed when battery gets weak.
EEE message when battery is flat.
If one actions the hatch when the battery is flat, no more display can happen.
Invert replacement battery polarity during 3 seconds (in this case only)
before connecting this new battery the right way.

Clock functions
Adjusting the date :
Open the hatch and wait for CAL
Press round button twice: CLOC is displayed
Press square then round button : year flashes
Arrow button to change year
Round button : day flashes
Arrow button to change day and month
Press square to complete procedure.
Adjusting the time :
Open the hatch and wait for CAL
Press round button twice: CLOC is displayed
Press square button : time flashes
Arrow button to change time
Press square as soon as displayed time is
correct
Close hatch.

Yes No
Do not clap

Enter lot number
Each strip box wears a sticker showing the lot number to be
displayed according to room temperature.
To enter or modify the lot number, open the hatch, press an
arrow button, to increase or decrease the lot number,
displayed in top right corner.
Close the hatch to save the new lot number.
Meter switches off.

Error message / checker
Test is carried on only on lot number 5.
White side first, then grey side
Result should be within the limits
printed at the back of the meter

Storage and handling of test strip
Container is always closed
Close container immediatly
Storage < 1 month : dry, 15 °c
Storage > 1 month : 4 – 8 °c

Open the hatch. The display briefly shows 8 8 8 8, then "CAL"
Lot number flashes.
Insert test strip in strip carrier
Pad downwards and facing the towards the meter body.
Close smoothly the hatch .Sign"---"displays.
If calibration is accepted, the meter beeps twice and displays "GO"
If not, "Err" is displayed
Only when everything is ready, open the hatch.
Exactly at 1st beep, dip test strip in solution.
Dipping lasts for 2 seconds exactly, not more, not less,
beetween 1 st bip and 3 rd bip (longer beep)
1st beep : dip the strip
3 rd beep : remove
Dipping duration = 2 seconds exactly
Calibration – Dipping

Shake the strip during 3 – 4 seconds to remove any remaining
excess solution.
Let the strip react . Do not touch, wipe or dab the test strip.
Within the 10 last seconds of countdown (not before) put the strip on
edge (only on edge) on an absorbing paper during 1 second only ,
to allow capilarity absorption of remaning solution.
This to avoid polluting the strip carrier
Insert test strip in strip carrier
Close smootly the hatch before the end of countdown.
You shouldn' t see the "SHUT" message.
Display " - - -" then result in mg/l NO3 (or ppm)

If result > 500 mg/l NO3
If result < 5 mg/l NO3
3 measures per sample
Calcule the average of 3 measures.
Example : 294 , 278, 300. Average = 290 mg/l
Check that the 3 measures are within limits of : -and + 10 % of this average.
Verification +/- 10 % : 261 – 319
The 3 measures are in the range 261 - 319.
Average is valid.
If the juice had been diluted 1/10, content = 2900 mg/L NO3.
Results

20 last results
in memory
Day Time Memory Week
TH 9 : 37 AM M Wk 2
47 ppm
Result ou mg/L

3 results on same sample

Maintenance - cleaning
Manipulate this instrument with care.
Avoid mecanical shocks, high or low temperatures, humidity.
Do not let moisture deteriorate the meter.
Remove battery before cleaning.