Hanna Instruments HI774

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Summary

General Description & Intended Use

Functional Description & LCD Display

Errors & Warnings

Light High

Indicates excess ambient light reaching the detector; check zero cuvette preparation.

Light Low

Indicates insufficient light for measurement; check zero cuvette preparation.

Under Range

Sample absorbs less light than reference; check procedure and cuvette use.

Inverted Cuvettes

Indicates cuvettes were inverted; swap them and repeat the measurement.

Over Range

Measured value exceeds method limits; dilute sample and repeat measurement.

Battery Low

Battery level is too low for proper function; replace the battery.

Drained Battery

Battery is completely drained; replace it and restart the checker.

Tips for an Accurate Measurement

Summary

General Description & Intended Use

Functional Description & LCD Display

Errors & Warnings

Light High

Indicates excess ambient light reaching the detector; check zero cuvette preparation.

Light Low

Indicates insufficient light for measurement; check zero cuvette preparation.

Under Range

Sample absorbs less light than reference; check procedure and cuvette use.

Inverted Cuvettes

Indicates cuvettes were inverted; swap them and repeat the measurement.

Over Range

Measured value exceeds method limits; dilute sample and repeat measurement.

Battery Low

Battery level is too low for proper function; replace the battery.

Drained Battery

Battery is completely drained; replace it and restart the checker.

Tips for an Accurate Measurement

The Hanna HI774 Marine Phosphate Ultra Low Range Checker HC is a handheld colorimeter designed for accurately determining phosphate levels in various applications, including aquaculture, drinking water, agriculture, and wastewaters. This device offers a single-button operation system, making it user-friendly, and features a large LCD for easy readability. Its auto shut-off function helps conserve battery life.

Function Description:

The HI774 operates by adapting the Ascorbic Acid Method, as described in the 20th Edition of Standard Methods for the Examination of Water & Wastewater. In this method, the reaction between phosphate and a specific reagent causes a blue tint to develop in the sample. The colorimeter then measures the intensity of this blue tint to determine the phosphate concentration.

Important Technical Specifications:

Range: 0.00 to 0.90 ppm
Resolution: 0.01 ppm
Accuracy: ±0.02 ppm ±5% of reading @ 25 °C (77 °F)
Light Source: Light Emitting Diode (LED) @ 525 nm
Light Detector: Silicon photocell
Environment: 0 to 50 °C (32 to 122 °F); RH max. 95% non-condensing
Battery Type: 1.5V AAA Alkaline (1 pc.)
Auto Shut-off: After 7 minutes of non-use and 2 minutes after reading
Dimensions: 86.0 x 61.0 x 37.5 mm (3.4 x 2.4 x 1.5″)
Weight: 64 g (2.3 oz)

Usage Features:

The HI774 is designed for straightforward operation. The measurement procedure involves a few simple steps:

Power On: Press the ON/OFF button to turn on the checker. The display will show all segments briefly, followed by "Add", "C.1" with "Press" blinking, indicating it's ready for the zero-point calibration.
Zero Calibration: Fill a cuvette with 10 mL of unreacted sample and cap it. Insert this cuvette into the checker and close the cap. Press the ON/OFF button. The display will show "Add", "C.2" with "Press" blinking, indicating the checker has been zeroed.
Reagent Addition: Remove the cuvette, unscrew the cap, and add the contents of one packet of HI774-0 Marine Phosphate Ultra Low Range reagent. Replace the cap and gently shake the cuvette for approximately 2 minutes until the powder is completely dissolved.
Measurement: Insert the reacted cuvette into the checker and close the cap. Press and hold the ON/OFF button. The display will show a countdown (2:59) prior to the measurement. Alternatively, you can wait 3 minutes and then press the button.
Reading: Once the timer ends, the checker will perform the reading and display the phosphate concentration in ppm. The instrument automatically turns off 2 minutes after displaying the reading.

Tips for Accurate Measurement:

Ensure the sample is free of debris.
The cuvette must be dry on the outside and free of fingerprints, oil, and dirt before insertion.
Wipe the cuvette thoroughly with a microfiber cleaning cloth (HI731318) or a lint-free cloth prior to insertion.
Avoid shaking the cuvette vigorously, as this can generate bubbles, leading to higher readings. Remove bubbles by swirling or gently tapping the cuvette.
Do not allow the reacted sample to stand too long after reagent addition, as this can affect accuracy.
Discard the sample immediately after reading to prevent permanent staining of the glass.

Error and Warning Messages:

The checker provides clear warning messages for erroneous conditions or when measured values are outside the expected range:

Light High (L.H): Indicates an excess of ambient light reaching the detector. Check the preparation of the zero cuvette.
Light Low (L.L): Indicates insufficient light for measurement. Check the preparation of the zero cuvette.
Inverted Cuvettes (InU): The sample and zero cuvettes are inverted. Swap them and repeat the measurement.
Under Range (0.00 blinking): The sample absorbs less light than the zero reference. Check the measurement procedure and ensure the same cuvette is used for both reference (zero) and measurement.
Over Range (0.90 blinking): The measured value exceeds the method limits. Verify the sample contains no debris and consider diluting the sample before repeating the measurement.
Battery Low (bAt): Battery level is too low for proper function. Replace the battery.
Drained Battery (bAd, then bAt): The battery is drained and must be replaced. Restart the checker after replacement.

Maintenance Features:

Battery Replacement: To replace the battery:
1. Turn off the checker by pressing and holding the ON/OFF button.
2. Turn the instrument upside down, use a screwdriver to unfasten the screw, and remove the battery cover.
3. Remove the old 1.5V AAA battery and replace it with a new one, inserting the negative end first.
4. Replace the battery cover, fasten, and tighten the screw.
A fresh battery provides a minimum of 5000 measurements. The checker automatically shuts down after 7 minutes of non-use and 2 minutes after a reading to conserve battery life.

Included Accessories:

The HI774 is delivered in a case with a custom insert and includes:

Sample cuvette and cap (2 pcs.)
Marine Phosphate Ultra Low Range reagent starter kit (reagents for 10 tests)
1.5V AAA Alkaline battery (1 pc.)
Instruction manual

It is recommended to save all packing material until you are certain the Checker® HC handheld colorimeter is working correctly, as any damaged or defective item must be returned in its original packing material with the supplied accessories.