Kern PLJ 420-3F precision balance 420 g / 0.001 g

The Kern PLJ is a series of precision balances with graphic display, formulation database and internal automatic adjustment. Six models weigh from 420 g to 6,200 g. Four models have a readability of 0.001 g (1 mg): the PLJ 420-3F, 720-3A, 1200-3A and 2000-3A. Two models have a readability of 0.01 g: the PLJ 4200-2F and the PLJ 6200-2A. The PLJ 2000-3A stands out. It weighs up to 2,100 g and reads to 1 mg; Kern calls it a milligram balance with a large weighing range for large samples or heavy tare containers.

Two weighing systems in one series

The PLJ 720-3A, 1200-3A, 2000-3A and 6200-2A operate with electromagnetic force compensation. The PLJ 420-3F and PLJ 4200-2F operate using strain gauges. For models with a readability of 1 mg, the linearity ranges from ± 0.002 g to ± 0.004 g. The stabilisation time is 2 s for the PLJ 720-3A, 1200-3A and 2000-3A, and 3 s for the other three models.

Formulation database and functions

The balance stores up to 99 formulations with up to 20 ingredients each, each with name and target value. The graphic display guides through the input in plain text. A high-stability mode and other filter settings are available as a dosing aid. In addition, there are piece counting with the reference piece counts 10, 25, 50 and 100 or free entry, percentage determination, density determination and a function for averaging under unstable weighing conditions. When weighing within a tolerance range, the balance emits an audible and a visual signal. GLP/ISO logging records the value, date and time. Data is transmitted to a printer or PC via the standard RS-232 interface.

Adjustment

According to the data sheet, the internal automatic adjustment system responds to a temperature deviation of 1.2 °C. It does not replace a calibration certificate, which is available separately (see below).

Draught shield and weighing chamber

The PLJ 420-3F, 720-3A and 1200-3A have a ring-shaped glass draught shield with a weighing chamber measuring Ø 150 mm and 60 mm in height; the balances are therefore 160 mm high. The PLJ 2000-3A has a large rectangular glass draught shield with a weighing chamber measuring 160 x 170 x 225 mm (W x D x H); the balance is 330 mm high and weighs approximately 7 kg. For the PLJ 4200-2F and PLJ 6200-2A, Kern does not list a draught shield; they are 120 mm high. The stainless steel weighing pan has a diameter of 110 mm for the PLJ 420-3F, 720-3A, 1200-3A and 2000-3A models, and 160 mm for the PLJ 4200-2F and 6200-2A models. For PLJ 720-3A, 1200-3A, 2000-3A and 6200-2A, an eyelet for below-balance weighing is included in the scope of delivery.

Typical applications

• Laboratory applications: weighing samples and standards to 1 mg
• Research and development: formulations from the formulation database with target values
• Jewellery and precious metals testing: density determination and weighing in the gram and carat range
• Environmental analysis: weighing samples with GLP/ISO protocol
• Electronics industry: counting small components

Anyone who wants to weigh large samples or heavy containers to 1 mg takes the PLJ 2000-3A. For weighing up to 720 g, the PLJ 420-3F and PLJ 720-3A are the smaller models. Anyone who wants to read to 0.01 g chooses the PLJ 4200-2F (up to 4,200 g) or the PLJ 6200-2A (up to 6,200 g).

Models at a glance

Technical details

These values apply to all models. Deviating values are given in the model table.

Scope of delivery

• Kern PLJ precision balance with stainless steel weighing plate
• Glass draught shield (not for PLJ 4200-2F and PLJ 6200-2A)
• Working protective cover
• Eyelet for below-balance weighing (PLJ 720-3A, 1200-3A, 2000-3A, 6200-2A)
• Plug-in mains adaptor with country adaptors for EU, AUS, UK, US and CH

Calibration

A DAkkS calibration certificate can be ordered separately: item no. 963-103 for PLJ 720-3A, PLJ 1200-3A and PLJ 2000-3A, item no. 963-127 for PLJ 420-3F and PLJ 4200-2F, item no. 963-104 for PLJ 6200-2A. The confirmation of manufacturer specification (969-517) is only available in conjunction with the DAkkS calibration certificate.

Warranty

According to Kern & Sohn, these devices come 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.

Downloads

• Operating instructions Kern PLJ (PDF)

Regulatory information

As electrical devices, the balances fall 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

Hook for below-balance weighing (PLJ-A02), density determination kit (ALT-A02, not for PLJ 6200-2A), working protective covers (PLJ-A01S05 with 5 pieces for all models; PLJ-A09 and PLJ-A09S05 with 5 pieces for all except PLJ 2000-3A), for the PLJ 2000-3A also ALJ-A01, ALJ-A04 and ALJ-A04S05 (5 pieces) as well as the ionisers ABP-A01, ALJ-A03 and YBI-01A, anti-vibration table (YPS-03), anti-vibration plates (YPS-04, YPS-05), thermal printers (YKC-01, YKH-01), dot-matrix printer (YKG-01), needle printer (YKT-01), RS232 Bluetooth adapter (YKI-02), RS232 Ethernet converters (YKI-10, YKI-11), RS232 WLAN converter (YKI-12) and the RS-232 interface cable (572-926) are also available. Kern also lists Safety Sets with test weights: 315-208-205 (20 g and 200 g, F1) for PLJ 420-3F, 315-109-206 (50 g F1 and 500 g E2) for PLJ 720-3A, 315-111-206 (50 g F1 and 1,000 g E2) for PLJ 1200-3A and 315-112-207 (100 g F1 and 2,000 g E2) for PLJ 2000-3A. For the PLJ 2000-3A there is also the test weight 316-12 (OIML class E2, 2 kg, compact form). Enquiries are handled via our procurement service.