KERN PNJ 3000-2M Precision Balance, tuning fork measurement system, internal calibration, suitable for verification (ex works only)

The Kern PNJ 3000-2M weighs up to 3,200 g and has a readability of 0.01 g. According to Kern, the tuning fork weighing system displays the value after approximately 3 seconds, whilst the internal adjustment runs automatically. The balance is suitable for weighing applications in pharmacies, laboratories and quality control, and can be ordered with verification.

Tuning-fork weighing system

In this weighing principle, a resonant body is set into oscillation electromagnetically in response to the load. Kern describes the system as robust and fast in its display. The stabilisation time is 3 s, the resolution is 320,000 steps, the reproducibility is 0.01 g and the linearity is ± 0.03 g. The USP minimum sample weight is 20 g (k = 2, U = 0.1 %).

Internal adjustment

The balance adjusts itself automatically using a built-in weight. External test weights are not required for routine use. After switching on, the instrument requires a warm-up time of 120 minutes; the permissible ambient temperature is 5 °C to 40 °C with a maximum relative humidity of 80 %.

Verification as an option

For the PNJ 3000-2M, conformity assessment according to NAWI 2014/31/EU is available ex works. The verification scale interval is 0.1 g, the minimum load is 0.5 g, and the accuracy class is II. Kern points out that verification must be ordered at the same time as the balance; subsequent conformity assessment is not possible. For verification, Kern requires the full address of the installation site. On a verified balance, the units g and ct are available; without verification, the additional units dwt, tl (Tw), tl (HK), ozt, tl (Singapore, Malaysia), mo, lb, oz and tol are also available.

Kern cites pharmacies as one of the areas of application. Where the weighing result is subject to mandatory verification, verification should therefore be part of the order.

Everyday functions

To count small parts, select a reference count of 10, 30, 50 or 100; automatic reference optimisation gradually improves the average part weight. The minimum part weight is 10 mg under laboratory conditions and 100 mg under standard conditions. The percentage calculation displays the deviation from the target value. During checkweighing, the balance visually indicates whether the weight is within tolerance. A bar displays the remaining available weighing range. The backlit LCD has digits 16.5 mm high; operation is via five buttons, and the preset unit is g. For carats, there is a dedicated range up to 16,000 ct with a readability of 0.1 ct.

The stainless steel weighing pan measures 190 x 190 mm and is shock-resistant. The plastic housing is 89 mm high; with a base area of 196 x 293 mm, it is compact enough for a workspace with limited room. A spirit level and adjustable feet are included. Data is transmitted to a PC or printer via the RS-232 interface. The balance generates a printout at the printer showing the value, date and time, which Kern describes as GLP-compliant.

Position within the PNJ range

The range includes two further models. The PNJ 600-3M weighs up to 620 g and has a readability of 0.001 g; its verification scale interval is 0.01 g and the minimum load is 0.02 g; the weighing surface has a diameter of 140 mm. The PNJ 12000-1M weighs up to 12,000 g, has a readability of 0.1 g, a verification scale interval of 1 g and a minimum load of 5 g, with the same weighing surface measuring 190 x 190 mm. The PNJ 3000-2M falls between these two. If you mainly weigh quantities ranging from a few grams to a few kilograms, this model is suitable. Anyone who needs to read to thousandths of a gram below 1 g needs the 600-3M; anyone weighing containers up to 12 kg needs the 12000-1M.

Typical applications

• Formulation and weighing in pharmacies, with verification
• Quality control and incoming goods inspection in the electronics and precision engineering industries
• Weighing and preparation in laboratory settings
• Dental laboratories
• Counting small parts, such as screws, seals or contacts

Technical details

Scope of delivery

• Kern PNJ 3000-2M precision balance with stainless steel weighing pan
• Mains adaptor with plug adaptors for the EU, UK, US, AUS and CH
• Protective working cover

Verification is not included as standard and must be ordered separately if required.

According to Kern & Sohn, this device comes with a 3-year warranty. Kern grants 3 years on products with a list price of €500 or more and 2 years on products below that and on components; wear parts such as batteries and rechargeable batteries are excluded. Warranty repairs are carried out by Kern or by a Kern dealer.

Regulatory information

As an electrical device, the balance falls under the ElektroG. The manufacturer Kern & Sohn GmbH is registered under the WEEE registration number DE 80821200. How to return old appliances is described on the page Environment and disposal.

Individual requirements and procurement service

RS-232 cables, printers, anti-vibration plates and a DAkkS calibration certificate are also available, as is the SCD-4.0 software for data transfer to a PC. Enquiries are handled via our procurement service.