The IP rating on a load cell tells you how well it resists dust and water. IP stands for “Ingress Protection,” and the two-digit number that follows breaks down into two separate scores: the first digit rates protection against solid particles like dust, and the second rates protection against liquids. An IP67 load cell, for example, is fully dust-tight (6) and can survive temporary submersion in water (7). Choosing the right IP rating for your environment is one of the most important decisions when selecting a load cell, because moisture or dust infiltrating the sensing element will destroy accuracy and shorten the cell’s life.
How the Two Digits Work
The IP code is defined by the international standard IEC 60529. The first digit ranges from 0 (no protection) to 6 (complete dust-tightness). For load cells, you’ll almost always see a 5 or a 6. A rating of 5 means dust can enter in small amounts, but not enough to interfere with safe operation. A rating of 6 means no dust gets in at all, verified by testing under vacuum for up to eight hours.
The second digit ranges from 0 (no liquid protection) to 8 (continuous submersion), with a special 9K rating at the top. Each step up represents a more aggressive water exposure: low-pressure sprays, jets from all angles, temporary submersion, prolonged submersion, and finally high-pressure, high-temperature washdown. The practical differences between these levels matter a lot depending on whether your load cell sits in a dry warehouse or gets steam-cleaned twice a day.
IP Ratings You’ll See on Load Cells
IP65
The 6 means full dust protection. The 5 means the cell can handle water jets from a nozzle at low pressure from any direction. This is the baseline for most industrial load cells and works well in clean, dry, indoor settings: warehouses, fulfillment centers, dry food packaging lines, and retail scales. If your equipment gets wiped down rather than washed, IP65 is typically sufficient and the most cost-effective option.
IP67
Same dust-tight rating, but the 7 means the load cell can survive full immersion in water up to 1 meter deep for 30 minutes. This is the go-to rating for outdoor applications like truck scales, agricultural platforms, and beverage facilities where the cell faces rain, snow, or occasional rinsing. IP67 gives you a meaningful step up in moisture protection without the cost of a full washdown-rated cell.
IP68
IP68 means the cell handles continuous submersion beyond the IP67 threshold. The exact depth and duration are set by the manufacturer but must exceed 1 meter or 30 minutes (or both). You’ll find IP68 load cells in applications where standing water, chemical exposure, or prolonged wet conditions are routine.
IP69K
This is the highest environmental protection rating available. IP69K-rated load cells withstand high-pressure water jets at 1,400 psi and temperatures up to 80°C (176°F), sprayed from multiple angles at close range. If steam cleaning, foam sanitizing, or power washing is part of your daily routine, IP69K is what you need. Meat processing, dairy, poultry, seafood, and pharmaceutical facilities all fall into this category.
Matching IP Ratings to Your Environment
The simplest way to choose is to match the rating to the worst conditions your load cell will regularly face:
- Clean, dry, indoor: IP65 minimum. Think packaging stations, retail counters, and storage facilities.
- Outdoor or occasional rinsing: IP67 minimum. Covers farming, beverage production, and any scale exposed to weather.
- Power wash or steam sanitation: IP69K. Required for meat, dairy, pharma, and any facility where hygiene regulations demand aggressive cleaning.
Choosing a higher IP rating than you need won’t hurt performance, but it will cost more. Choosing too low a rating is the expensive mistake, because moisture damage to a load cell’s strain gauges often shows up as gradual drift in readings before the cell fails entirely.
How Load Cells Achieve Their IP Rating
The IP rating isn’t just about the metal housing. It depends on how the internal sensing elements are sealed, and there are several approaches with very different capabilities.
The most basic method is environmental sealing: rubber boots, adhesive on the cover plate, or potting compound filling the gauge cavity. This blocks dust and debris effectively and offers moderate humidity resistance, but it won’t protect against water immersion or pressure washing. Load cells with this type of sealing top out around IP65.
For higher ratings, manufacturers use welded barriers. The cable entry point is a common weak spot because moisture can wick along the cable strands and into the cell. Weld-sealed load cells close off the instrumentation area with a welded cap or sleeve, preventing this. In fully hermetic designs, every potential entry point (including the cable exit) is laser-welded shut. These cells reach IP68 and IP69K ratings and last significantly longer in corrosive or wet environments, though they cost more.
Material Matters
The load cell’s construction material directly limits the IP rating it can achieve. Stainless steel load cells typically come with IP68 or IP69K ratings because the material can be hermetically welded and resists corrosion on its own. Aluminum load cells are lighter and less expensive, but they’re generally rated IP65 or lower because aluminum is harder to seal at the same level and more vulnerable to chemical corrosion.
If your application involves any kind of washdown, chemical contact, or outdoor exposure, stainless steel with a higher IP rating will almost always be the better long-term investment. The upfront cost difference is small compared to replacing a corroded aluminum cell mid-production.