Soil Temperature Probe

LPSTP Digital Stem Thermometer – Built for Agriculture, Horticulture and More

A thermometer designed to withstand the rigours and demands of agriculture and horticulture, particularly when monitoring soil temperatures and predicting pasture and crop growth, should ideally meet the following criteria.

For laboratory, industrial and food-processing temperature monitoring, it supports critical  laboratory cryogenic storage, sterilization, and incubator monitoring  within the  -20°C to -10°C temperature range with ±0.4°C accuracy , while its IP68 waterproofing ensures reliability in harsh environments. 

The ideal thermometer needs to be:
Waterproof ✓
Rugged ✓
Accurate ✓
Portable ✓
Quick-acting ✓
Easy to use ✓
Affordable ✓

Finding a thermometer that ticks all these boxes is harder than you might think. There are plenty of inexpensive units available, but they invariably fall short in two important areas: durability and, closely followed, accuracy and ongoing measurement consistency.
There's simply too much at stake when growing pastures, crops and other plants to leave temperature measurements to guesswork.

We believe we've found an admirable contender in the LPSTP Digital Stem Thermometer. This unit more than meets the requirements listed above and should provide many years of reliable service.

Available in Two Stem Lengths

The LPSTP is available in two stem lengths:
150mm – likely to suit most applications.
300mm – ideal when temperatures need to be measured at greater depths.

Accurate, Responsive and Versatile

The LPSTP thermometer measures temperatures from -50°C to +330°C, with Fahrenheit available as a switchable display option.
Its measurement accuracy is an impressive ±0.4°C between -10°C and +100°C. Most inexpensive digital thermometers struggle to achieve accuracy within even twice this margin!
Readings are displayed in 0.1-degree increments and update every second.
The thermometer also records and displays the highest and lowest temperatures over a given period. This makes it useful for applications beyond agriculture and horticulture, such as monitoring the performance of coolstores and refrigerators.

Convenient and Easy to Operate

Each unit comes supplied with a CR2032 battery already installed.
It features a manual on/off switch and will automatically power off after 10 minutes if left running. There is also an option to disable the automatic power-off function if continuous monitoring is required.
The thermometer comes factory calibrated, but should the need arise, it can also be recalibrated by the user via its built-in calibration function.
We wouldn't recommend recalibrating without good reason, but having this capability is a particularly useful feature and a relatively rare inclusion at this price point.
Our own testing confirms that the units arrive properly calibrated from the factory and measure well within their specified accuracy at both 0°C and 100°C.

Laboratory-Grade Performance Without the Laboratory-Grade Price

In terms of measurement performance, these thermometers deliver the sort of results you'd expect from a laboratory-grade instrument, but at a fraction of the cost.
A significant part of the price of certified laboratory-grade thermometers relates to their formal certification and associated testing. The LPSTP offers excellent measurement performance without that additional expense.

Built to Last

This thermometer is genuinely pleasant to use. The display is clear, and its performance is crisp and responsive.
The large buttons are easy to access and provide positive, precise operation without being overly sensitive to accidental bumps or brushing.
Large button battery capacity provides thousands of hours of use before replacement is required.
The probe shaft is constructed from sturdy 4mm-diameter stainless steel, tapering to 2.6mm at the tip, where temperature measurement takes place. This narrower tip helps facilitate faster response times.
Particular attention has also been given to reinforcing the housing where the probe shaft enters the instrument. This is a common failure point in cheaper thermometers, so the additional reinforcement is a welcome design feature.
IP68 Waterproof Protection

The LPSTP has an IP68 waterproof rating, placing it at the top end of the commonly used IP protection classification system.
The two digits represent:
6 – Dust-tight: Complete protection against the ingress of dust and other solid particles.
8 – Water protection: Protection against continuous immersion in water under conditions specified by the manufacturer, generally beyond one metre in depth.
The housing is manufactured from ABS plastic, a tough and durable material well suited to demanding working environments.
The keys are made from a heavy-duty rubber membrane, while the battery compartment features a secure bayonet-style screw cap incorporating a properly recessed rubber O-ring to help maintain its waterproof seal.

Everything You Need Included

Each thermometer comes complete with:

• Protective sheath for the probe and tip.
• Instruction manual.
• Handy reference booklet covering temperature requirements for various plants and cropping applications.

In short, the LPSTP Digital Stem Thermometer offers an impressive combination of accuracy, durability, waterproof protection and ease of use at an affordable price. Whether you're monitoring soil temperatures, managing pasture and crop growth, or checking temperatures in industrial and food-processing environments, it's a versatile and dependable instrument worth considering.