Hanna Instruments HI-981421-02 Groline 24 Hour Hydroponics Monitor for pH, EC/TDS and Temperature for in-line applications
The Groline HI-981421 monitor provides 24 hour continuous monitoring of pH, Conductivity (EC or TDS), and temperature in hyproponic nutrients.
Quick to setup and simple to use, this monitor was designed with hydroponics, aquaponics, and greenhouses in mind.
Make your nutrient solution easy to manage with the Groline monitor and combined pH/EC/temperature probe.
Instantly view all measurements
The versatile display of the Groline monitor allows for three screen modes. The LCD can display all three essential hydroponic nutrients measurements at one time, a 3-second cycle of single measurements, or a real-time graph screen with options for measurement selection and log recall.
Monitor changes over time
Fluctuations in your hydroponic nutrient solution can have lasting effects on your plants. The Groline monitor automatically logs every 15 minutes for 30 days, and stores min, max and average values so you can recognise when patterns arise and help prevent future problems. For review and storage, use the USB-C to easily transfer data to a flash drive or PC using a cable. Files are exported as .csv.
Grow with confidence
The Groline monitor frees up your time by doing the testing for you. Simply set high and low alarm levels – if your hydroponic nutrient solution moves out of range a measurement error will display. A quick look at the large display will let you know if your nutrient solutions needs adjusting.
Features
- Can be integrated into a fertiliser system
- pH/EC inline probe with built-in temperature sensor
- IP65 rated enclosure designed to withstand harsh growing environment
- Selectable EC to TDS conversion factor: Choice of either a 0.5 or 0.7 conversation factor
- Automatic Temperature Compensation
- Large LCD with plant-friendly green backlighting
- Ambient light sensor for automatic LCD dimming
- Quick calibration using Quick Cal solution simultaneously for pH and EC
- Calibration reminder
- Data logging for 30 days – logs every 15 minutes
- Set up, calibration and operating parameters are stored in non-volatile memory. All settings are retained if power is lost
- 24 hour summary screen (plot and details)
- GLP feature calibration data for the pH and EC (up to 5 calibrations)
- Alarms feature for all parameters
On-screen features
- On-screen help at the push of a button
- High and low alarms
- Easy menu navigation
- Data viewing
- Data Transfer
- Calibration timeout
- GLP
About the Inline probe
The supplied HI-1285-9 multiparameter probe measures pH, EC and temperature in one convenient, rugged probe.
A solid-state preamplifier is integrated into the probe to protect the pH measurement from transient electrical noise. Sources of electrical noise include ballasts used in lighting and pumps to circulate water and nutrient solutions. The HI-1285-9 incorporates two graphite EC sensors for reliable conductivity readings.
Specifications
| pH Specifications | |
|---|---|
| pH Range | 0.00 to 12.00 pH |
| pH Resolution | 0.01pH, (0.1pH) |
| pH Accuracy | ±0.05pH, (±0.1pH) |
| pH Calibration | one or two points calibration using standard buffers (pH4.01, 7.01, 10.01), using auto-buffer recognition, one-point calibration using quick calibration solution |
| Temperature Compensation | Automatic |
| Conductivity – EC/TDS Specifications | |
| EC Range | 0.00 to 10.00 mS/cm |
| EC Resolution | 0.01mS/cm |
| EC Accuracy | ±0.1 mS/cm (0.00 to 5.00 mS); ±0.2 mS/cm – 5.00 to 10.00 mS/cm) |
| EC Calibration | Automatic recognition, one-point at 1.41 mS/cm or 5.00 mS/cm, one point calibration using quick calibration solution |
| EC/TDS Temperature compensation | Automatic with β set at 1.9%/°C |
| TDS Range | 0 to 5000 ppm (TDS conversion factor 0.5 (0.5 CF)); 0 to 7000 ppm (TDS conversion factor 0.7 (0.7 CF)) |
| TDS Resolution | 10ppm |
| TDS Accuracy | ±2% f.s. |
| Temperature Specifications | |
| Temperature Range | 0.0 to 60.0°C |
| Temperature Resolution | 0.1°C |
| Temperature Accuracy | ±0.5°C |
| General specifications | |
| Display | 128 x 64 pixel B/W LCD with green backlight |
| Connectivity | USB Type-C – Export on flash drive/PC |
| IP Rating | IP65 |
| Alarms | High and low with enable/disable option for all parameters |
| Data storage | Automatic logging for last 30 days at 15 minute intervals |
| GLP | Last 5 calibrations – pH and EC |
| Probe | HI-1285-9 triple junction in-line pH/EC/TDS temperature PVC, pre-amplified multiparameter probe with internal temperature sensor, DIN connector and 3m cable |
| Probe Max Pressure | 8 bar |
| Probe range | 0 to 12pH |
| Probe dimensions/weight | 187 x 25 x 25mm/191g |
| Power supply | 12VDC adapter (included) |
| Environment | -5 to 50°; RH max 95% non-condensing |
| Dimensions | 125 x 185 x 38mm |
| Weight | 333g |
| Ordering Information | HI-981421 is supplied with HI-1285-9 multi-parameter probe, HI-50036-0 Quick Cal buffer solution sachet (2), HI-700661 pH electrode cleaning solution sachet for agriculture (2), DC Power adapter (1), and instructions. |
| Warranty | 2 years (probe 6 months) |
| Compatible solutions: | HI-50036p Quick Calibration Solution for GroLine pH and EC Meters, 25 sachets; HI-5036-023 Quick Calibration Solution for GroLine pH and EC Meters, 230 mL; HI-700661 GroLine Cleaning Solution for agriculture, 230 mL; HI-70300-023 GroLine Electrode Storage Solution, 230 mL. HI-7004-023 GroLine pH 4.01 Calibration Buffer, 230 mL; HI-7007-023 GroLine pH 7.01 Calibration Buffer, 230 mL; HI-7010-023 GroLine pH 10.01 Calibration Buffer, 230 mL. |
Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.