£493.20 £591.84 (Inc. VAT)
HI-99121 Waterproof pH & temperature meter for direct measurement in soil
The HI-99121 portable pH meter, together with HI-12923 pH electrode, is designed to measure
pH in soil or soil slurries.
The HI-99121 is a lightweight, portable pH and temperature meter. It features a two button
operation system and is simple to use. It has a waterproof and compact casing, large dual-
line display, and automatic pH calibration at one or two points.
About Soil pH:
acidic) to 14 (basic) with pH 7 being neutral. Soil can be acid, neutral or
alkaline soils. Nevertheless, every plant has a target for optimum growth.
and plants in the soil.
supplying nutrients to the plants, have a preference for moderately acidic or slightly
alkaline soils. In fact, in strongly acidic conditions, nitrogen fixing and the
mineralisation of vegetable residual is reduced. Plants absorb the nutrients dissolved in
the soil water and the nutrient solubility depends largely on the pH value. Hence, the
availability of elements is different at varying pH levels.
requires a particular range of pH to optimise its growth.
means that plants needs these elements should theoretically be in an acidic type of soil.
Nitrogen, phosphorus, potassium and sulphur, on the other hand, are readily available in a
pH range close to neutrality.
example, a plant may not tolerate an excess of aluminium ions that may increase under acidic
conditions. When pH values are too far from neutral conditions a less permeable and more
compact soil may result.
The electrode, auger & soil prep solution explained
HI-12923 has a conical rugged tip. It has a built-in temperature probe for temperature
compensated pH readings and an integrated pre-amplifier to provide measurements impervious
to noise and electrical interferences.
The HI-721319 auger for ground penetration is supplied to loosen the soil prior to any
measurements being taken. The use of the auger is recommended to prevent scratching to the
For best results, it is recommended that soil tests be carried out using a prepared soil
slurry using the HI-7051 soil sample preparation solution, rather than direct €˜in the field€™
measurements – although this is possible following the instructions and use of the included
|pH Range||-2.00 to 16.00 pH*|
|Temperature Range||-5.0 to 105.0°C / 23.0 to 221.0°F|
|pH Resolution||0.01 pH|
|Temperature Resolution||0.1°C / 0.1°F|
|pH Accuracy||±0.02 pH|
|Temperature Accuracy|| ±0.5°C (up to 60°C), ±1°C (outside);
±1.0°F (up to 140°F), ±2°F (outside)
|pH Calibration|| automatic, 1 or 2 point with 2 sets of memorised buffer values
(pH 4.01 / 7.01 / 10.01 or pH 4.01 / 6.86 / 9.18)
|Temperature Compensation||Automatic, -5 to 105°C (23 to 221°F)|
|pH Electrode||HI 12923 preamplified pH and temperature probe with conical tip,
DIN connector and 1 m (3.3′) cable (included) – The HI-12923 is limited to be used from 0
to 12 pH and from -5 to 70°C
|Battery Type / Life||3 x 1.5V AAA / approx. 1400 hours of continuous use:
auto-off after 8 minutes of non-use
|Environment||0 to 50°C (32 to 122°F); RH max 100%|
|Dimensions||154 x 63 x 30 mm (5.9 x 3.1 x 1.4″)|
|Case ingress protection rating||IP67|
Please call for more information on this product.