Direct Soil Measurement pH Portable Meter
R18,355.00 Excl. VAT
Measure soil pH directly in the ground with the HI99121 and its pre-amplified HI12923 electrode, whose rugged conical tip goes straight into moist or soft soil, with a plastic auger supplied for harder ground. The waterproof meter reads pH to ±0.02 pH alongside temperature, with automatic temperature compensation and automatic calibration, and comes complete with buffers, cleaning solutions and a hard carrying case. Lead time is 4 weeks.
- Description
- Additional information
Description
Direct Soil pH Measurement, Without the Wait
Soil pH decides how much of each nutrient a plant can actually take up. Most plants prefer a range between 5.5 and 7.5, though every species has its own optimum. Get it wrong and the consequences show up in the crop: iron, copper and manganese stop being soluble in alkaline conditions, while strongly acidic soil can release enough aluminium to damage the plant. Acidity also suppresses the bacteria that fix nitrogen and break down organic matter, and pushes soil structure toward compaction.
A laboratory soil test answers all of this, but it takes days or weeks. The HI99121 answers it on the spot.
Supplied with: HI12923 pH electrode, HI721319 soil auger, HI7051M soil preparation solution (230 mL), HI70004 pH 4.01 buffer sachet (20 mL), HI70007 pH 7.01 buffer sachet (20 mL), HI700663 cleaning solution for inorganic soil deposits (20 mL), HI700664 cleaning solution for organic soil deposits (20 mL), 100 mL plastic beaker, batteries, instructions and hard carrying case.
Built for Soil, Not Adapted to It
The supplied HI12923 electrode is purpose-built for soil work. Its conical, reinforced tip is designed to be inserted directly into moist or soft ground, so there is no need to prepare a slurry for a routine check. On hard or stony soil, use the included auger to open a hole first, which protects the glass from impact. For the most reliable readings, wet the sample with the supplied HI7051M soil preparation solution before measuring.
The electrode carries a built-in temperature sensor, so the meter compensates automatically for temperature variation across a site or a working day. It is also refillable: turning the cap creates positive head pressure, letting fresh reference electrolyte flow through the junction. That keeps response times short and extends the working life of the electrode well beyond a sealed gel design.
Features
- Pre-amplified soil electrode for fast, stable readings immune to humidity-driven electrical noise
- Direct insertion into moist or soft soil with a rugged conical tip, no slurry preparation needed
- Automatic temperature compensation from a temperature sensor built into the electrode
- Automatic calibration at one or two points with buffer recognition
- Refillable electrode with positive head pressure for faster response and longer service life
- BEPS battery error prevention warns before low power affects readings
- Battery percentage on start-up so you know your remaining runtime before leaving base
- HELP function with on-screen tutorial messages
- CAL Check probe condition indicator flags a deteriorating electrode
- IP67 waterproof, compact and heavy-duty
- Quick-connect DIN electrode on a 1 m cable for tool-free replacement
- Soil auger included for stony or compacted ground
Specifications |
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|---|---|
| SKU | HI99121 |
| pH range | −2.00 to 16.00 pH / −2.0 to 16.0 pH |
| pH resolution | 0.01 pH / 0.1 pH |
| pH accuracy | ±0.02 pH / ±0.1 pH |
| pH calibration | Automatic, one or two points, two buffer sets (4.01 / 7.01 / 10.01 or 4.01 / 6.86 / 9.18) |
| pH temperature compensation | Automatic, −5.0 to 105.0°C (23.0 to 221.0°F) |
| Electrode diagnostics | CAL Check probe condition indicator |
| mV range | ±825 mV |
| mV resolution | 1 mV |
| mV accuracy | ±1 mV |
| Temperature range | −5.0 to 105.0°C / 23.0 to 221.0°F |
| Temperature resolution | 0.1°C / 0.1°F |
| Temperature accuracy | ±0.5°C up to 60°C, ±1.0°C outside (±1°F up to 140°F, ±2.0°F outside) |
| pH electrode | HI12923 glass body pre-amplified soil electrode with internal temperature sensor, quick-connect DIN, 1 m cable (included) |
| Automatic shut-off | User selectable: 8 minutes, 60 minutes, or disabled |
| Battery type and life | 3 × 1.5V AAA, approximately 1400 hours continuous use |
| IP protection | IP67 |
| Operating environment | 0 to 50°C (32 to 122°F), RH max 100% |
| Dimensions | 154 × 63 × 30 mm (6.1 × 2.5 × 1.2″) |
| Meter weight | 196 g |
| Shipping weight | 1.47 kg |
| Lead time | 4 weeks |
Why an Amplified Electrode Matters in the Field
This is the feature that separates the HI99121 from a standard portable pH meter, and it is worth understanding before you buy.
A conventional pH electrode produces an extremely small, high-impedance signal. Between the electrode tip and the meter, that signal is vulnerable. Humidity, damp cabling, static and nearby electrical equipment all introduce noise, which shows up as readings that drift, wander or refuse to settle. Anyone who has stood in a wet field waiting for a number to stabilise has met this problem.
The HI12923 is pre-amplified, meaning the signal is boosted inside the electrode itself, before it travels down the cable. A stronger signal is far harder to corrupt. The practical result is a fast, stable response that stays immune to the electrical noise humidity would otherwise cause, so readings settle quickly and hold steady in exactly the damp conditions where soil testing happens.
The electrode connects by quick-connect DIN fitting on a 1 metre cable, so it can be swapped without tools.
Designed for a Full Day’s Work
The meter shows pH and temperature simultaneously on a large multi-level display, alongside calibration status and stability indicators. Calibration is automatic at one or two points, with buffer recognition across two standard sets, so there is no menu-hunting between samples. On-screen tutorial messages walk you through each step, and a HELP function is available if you get stuck.
Battery percentage appears at start-up so you know what you have left before you drive out, and the Battery Error Prevention System warns you if power has dropped far enough to affect accuracy, rather than letting you record a bad number. Three AAA batteries give roughly 1400 hours of continuous use. The housing is IP67 rated, compact and heavy-duty.
Usage note: On stony ground, use the soil auger to open a hole before inserting the probe, to avoid damaging the glass. For best accuracy, ensure the soil is wet, using the HI7051M soil preparation solution where needed.
Additional information
| Weight | 1 kg |
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| Dimensions | 15 × 7 × 5 cm |
