The HI96700C is a portable microprocessor-based photometer designed for accurate measurement of ammonia-nitrogen (NH₃-N) in water samples. This instrument is part of Hanna Instruments' HI96 series of colorimeters, which utilize a special tungsten lamp and a narrow band interference filter to ensure precise and repeatable readings. The advanced optical system is factory calibrated and electronically and optically designed to minimize the need for frequent recalibration.
Function Description
The HI96700C operates on the principle of absorption of light, where the intensity of light passing through a sample is measured. The instrument uses a tungsten lamp as a light source and a silicon photocell with a narrow band interference filter at 420 nm as the light detector. When the ammonia-nitrogen reagent is added to the sample, a yellow tint develops, and the intensity of this color is directly proportional to the concentration of ammonia-nitrogen. The microprocessor converts the incoming value into the desired measuring unit and displays it on the LCD.
The device features a user-friendly interface with several keys for operation:
- GLP/▲ key: A multi-functional key used to enter GLP mode, edit the desired year, and edit the desired month. In measurement mode, it makes a measurement.
- CAL CHECK key: A bi-functional key used to perform the validation of the meter or to enter calibration mode. Pressing for three seconds initiates calibration.
- ZERO/CFM key: A bi-functional key used to zero the meter prior to measurement or to confirm edited values. In calibration mode, it confirms factory calibration restore.
- READ/►/TIMER key: A multi-functional key used to make a measurement, press for three seconds to start a pre-programmed countdown prior to measurement, or to enter factory calibration restore.
- ON/OFF key: Turns the meter on and off.
The Liquid Crystal Display (LCD) provides various information, including:
- Measuring scheme (lamp, cuvette, detector)
- Error messages and warnings
- Battery icon indicating charge state
- Hourglass icon indicating an internal check
- Status messages
- Chronometer for reaction timer
- Month, day, and date icons
- Four-digit main display for measurement values
- Measuring units (mg/L)
- Four-digit secondary display
The HI96700C supports three operating modes:
- Measurement mode: Default operation mode, enabling both validation and measurement.
- Calibration mode: Entered by pressing CAL CHECK for three seconds, allowing for calibration of the instrument.
- GLP mode: Entered by pressing GLP/▲, providing access to user calibration date or factory calibration restore.
Important Technical Specifications
- Range: 0.00 to 3.00 mg/L NH₃-N
- Resolution: 0.01 mg/L NH₃-N
- Accuracy: ±0.04 mg/L ±4% of reading @25 °C (77 °F)
- Light Source: Tungsten lamp
- Light Detector: Silicon Photocell with narrow band interference filter @420 nm
- Method: Adaptation of ASTM Manual of Water and Environmental Technology D1426 Nessler method. The reaction between ammonia and reagent causes a yellow tint in the sample.
- Environment: 0 to 50 °C (32 to 122 °F); max 95% RH non-condensing
- Battery Type: 9V (1 pc.)
- Auto-Shut Off: After 10' of non-use in measurement mode; after 1 hour of non-use in calibration mode; with last reading reminder.
- Dimensions: 192 x 104 x 69 mm (7.6 x 4.1 x 2.7")
- Weight: 320 g (11.3 oz.)
Usage Features
The HI96700C is designed for ease of use with a clear, step-by-step measurement procedure:
- Startup: Turn the meter on by pressing ON/OFF. The display briefly shows all tags.
- Zeroing: Fill one cuvette up to the 10 mL mark with unreacted sample and replace the cap. Place the cuvette into the cuvette holder, ensuring the notch on the cap is positioned securely in the groove. Press ZERO/CFM. The meter will zero and display "-0.0-".
- Reagent Addition: Add 4 drops of HI93700A-0 liquid reagent to the zeroed sample, replace the cap, and swirl to mix. Then, add 4 drops of HI93700B-0 liquid reagent, replace the cap, and swirl to mix.
- Measurement: Place the cuvette back into the holder. Press and hold READ/►/TIMER for three seconds to start the countdown. Alternatively, wait for 3 minutes and 30 seconds, then press READ/►/TIMER. The instrument will display the concentration in mg/L of ammonia nitrogen (NH₃-N). To convert to mg/L of ammonia (NH₃), multiply the displayed value by a factor of 1.214.
Validation Procedure:
The instrument can be validated using CAL Check™ Standards (HI96700-11).
- Turn the meter on by pressing ON/OFF.
- Place CAL Check™ Standard Cuvette A into the cuvette holder.
- Press ZERO/CFM. The meter will zero and display "-0.0-".
- Remove Cuvette A. Place CAL Check™ Standard Cuvette B into the cuvette holder.
- Press CAL CHECK. The display will show the validation standard value. The reading should be within specifications as reported in the CAL Check™ Standard Certificate.
Calibration Procedure:
- Turn the meter on by pressing ON/OFF.
- Press and hold CAL CHECK for three seconds to enter calibration mode. The display will show "CAL" during calibration procedure.
- Place CAL Check™ Standard HI96700-11 Cuvette A into the cuvette holder.
- Press ZERO/CFM. The meter will zero and display "-0.0-".
- Remove Cuvette A. Place CAL Check™ Standard HI96700-11 Cuvette B into the cuvette holder.
- Press READ/►/TIMER. After three seconds, the display will show the CAL Check™ Standard value.
- Date Input: Press GLP/▲ to edit the desired year. Press ZERO/CFM or READ/►/TIMER to confirm. Repeat for month and day. Press ZERO/CFM to save the calibration date. The instrument will display "Stor" and then return to measurement mode.
GLP (Good Laboratory Practice) Features:
The GLP mode allows verification of the last calibration date and restoration of factory calibration.
- To display the calibration date, press GLP/▲.
- To restore factory calibration, press GLP/▲, then READ/►/TIMER to confirm. Press ZERO/CFM to abort. The instrument will display "donE" upon restoration.
Maintenance Features
Battery Management:
The instrument automatically shuts down after 10 minutes of non-use in measurement mode and after 1 hour of non-use in calibration mode. The battery icon on the display indicates the charge level:
- 3 lines for 100 % capacity
- 2 lines for 66 % capacity
- 1 line for 33 % capacity
- Battery icon blinking indicates capacity is under 10 %
- "dEAd bAtt" indicates a dead battery, requiring replacement.
Battery Replacement:
- Turn the instrument off by pressing ON/OFF.
- Turn the instrument upside down and remove the battery cover by turning it counterclockwise.
- Extract the battery and replace it with a fresh one.
- Insert the battery cover and turn it clockwise to close.
General Tips for Accurate Measurement:
- Ensure the cuvette is placed into the measurement cell dry, outside and completely free of fingerprints, oil, or dirt. Wipe thoroughly with HI731318 or a lint-free cloth.
- Avoid shaking the cuvette excessively, as this can generate bubbles and cause higher readings.
- Do not let the reacted sample stand too long after reagent is added, as accuracy will be lost.
- It is recommended to take multiple readings in a row and use the same cuvette for zeroing and measurement.
- Discard the sample immediately after reading, as the glass might become permanently stained.
- Reaction times reported in the manual are at 25 °C (77 °F). Higher temperatures decrease reaction times, while lower temperatures increase them.
- For maximum accuracy, follow the validation procedure before each measurement.
Accessories:
- Reagent Set: HI93700-01 (100 tests), HI93700-03 (300 tests)
- CAL Check™ Standard Cuvettes: HI96700-11 (1 set)
- 9V battery: HI740029P (10 pcs.)
- Cloth for wiping cuvettes: HI731318 (4 pcs.)
- Glass cuvettes: HI731331 (4 pcs.)
- Caps for cuvettes: HI731335 (4 pcs.)
- Carrying case: HI740318
- Cuvette cleaning solution: HI93703-50 (230 ml)
The HI96700C is a robust and reliable instrument, backed by a two-year warranty for defects in workmanship and materials. Hanna Instruments provides technical support via email at tech@hannainst.com and maintains a worldwide contact list at www.hannainst.com.
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