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Key: test item, instrument name, total nonvolatile migration, gravimeter, moisture permeameter

Product

Water Bath Constant‑Weight Analyzer for Total Migration & Loss on Drying

ERT- 121 /181/ 231 -C
Focusing on packaging and material testing technology, we are committed to quality control in industries such as healthcare, pharmaceuticals, food, packaging, textiles, and new materials. Our products are widely used in enterprises, testing institutions, universities, and research institutes.

Category:

Constant Weight Analyzer

Water Bath Drying Constant Weight

Water Bath Constant‑Weight Analyzer for Total Migration & Loss on Drying

Automated Evaporation‑Drying‑Weighing Workstation - Model ERT‑C Series

Overview

The LabStone ERT‑C Series is a fully automated workstation designed specifically for total migration testing of food contact materials, non‑volatile residue determination, and loss on drying / moisture analysis. It replaces the traditional, labor‑intensive workflow of water baths, drying ovens, desiccators, and analytical balances with a single, compliant, and unattended process.

Engineered for pharmaceutical, food contact material, and contract testing laboratories, the ERT‑C Series ensures pharmacopoeia‑grade constant‑weight results with high throughput and minimal operator intervention.

Key Applications

Food Contact Materials (Total Migration)

Gravimetric determination of total migration from plastics, paper, and multilayer packaging into food simulants (aqueous, acidic, alcoholic).
Compliance testing with GB 31604.8, EU Framework Regulation, and other global migration requirements.

Pharmaceutical Packaging (Non‑Volatile Residue)

Extractables screening of container‑closure systems.
Non‑volatile residue testing of elastomeric closures, flexible films, and laminates per YBB standards.

Pharmaceutical & Chemical QC (Loss on Drying)

Loss on Drying (LOD) of APIs, excipients, and bulk drugs per USP <921> and Ph. Eur. 2.2.32.
Moisture content determination in powders, granules, and solid dosage forms.

Food & Beverage QC

Moisture analysis of dairy powders, starches, cereals, and dehydrated foods per GB 5009.3.
Total solids / dry residue testing of bottled water and beverages per GB 8538.

Working Principle

The ERT‑C Series executes a fully automated four‑stage constant‑weight cycle:

1.Water‑Bath Evaporation

Test portions (food simulant, extract solution, or aqueous sample) are gently evaporated to near‑dryness in a controlled water bath (ambient to 100 °C). Indirect heating prevents bumping and thermal degradation.

2.High‑Temperature Drying

Vessels are transferred to a precision drying chamber (ambient to 140 °C) to remove residual moisture and volatile matter.

3.Low‑Humidity Cooling

Vessels are cooled in a patented chamber maintained at < 20% RH, preventing moisture reabsorption-an inherent weakness of manual desiccator methods.

4.Constant‑Temperature Weighing

A METTLER TOLEDO analytical balance (0.1 mg readability) weighs the vessels. The system repeats the dry–cool–weigh cycle until constant weight (≤ 0.3 mg difference over two cycles) is achieved, then calculates residue mass, migration level, or moisture content.

Compliance Standards

ISO 759 - Plastics - Determination of loss of volatile matter

USP <921> - Loss on Drying

Ph. Eur. 2.2.32 - Loss on Drying

EP 9.0 - Water, Purified

ASTM D5404 / ASTM D6447 - Moisture content by oven drying

GB 31604.8 - Food contact materials - Determination of total migration

GB 5009.3 - National food safety standard - Determination of moisture in foods

GB 8538 - National food safety standard - Examination of drinking natural mineral waters

GB/T 9740 - Chemical reagents - Determination of evaporation residue

GB/T 2914 - Plastics - Determination of volatile matter

GB 5413.39 - Determination of insoluble dietary fiber in foods

GB/T 5750.4 / DZT 0064.9 / GB/T 14415 - Water and mineral analysis

ChP General Provisions - Constant‑weight requirement

ChP Part IV - Extractives determination method, Loss on Drying, Total Solids

ChP Part II - Purified Water

YBB 00342002 - Evaporation residue of pharmaceutical packaging

YBB 00132002 - Non‑volatile matter of pharmaceutical packaging

Key Features

Fully Automated 4‑in‑1 Workflow

Integrates water‑bath evaporation, drying, low‑humidity cooling, and weighing into a single, unattended process.

Pharmacopoeia‑Grade Constant Weight

Achieves 0.3 mg constant weight within two drying cycles, fully aligned with USP, Ph. Eur., and ChP requirements.

Scalable Workstation Configurations

Available with 12, 18, or 23 workstations, supporting small to medium‑scale QC and research laboratories.

Patented Balance Protection

Thermal isolation, moisture‑proofing, and anti‑corrosion technologies protect the METTLER TOLEDO balance from heat, vapor, and corrosive residues.

Low‑Humidity Cooling Chamber

Maintains <20% RH during cooling, eliminating moisture reabsorption errors common in manual methods.

Safe & Reliable Operation

Indirect heating, over‑temperature power‑off protection, and water‑level monitoring ensure safe handling of flammable solvents and acidic simulants.

Dual Test Modes
Constant‑Weight Mode (auto‑terminates at ≤ 0.3 mg) and Constant‑Time Mode (fixed drying duration).
GMP‑Ready (Optional)

Optional Computerized System Module provides user management, electronic signatures, and audit trails compliant with 21 CFR Part 11 and NMPA GMP.

High‑Efficiency Solvent Recovery (Optional)

Captures up to 95% of evaporated solvents (ethanol, acetic acid), reducing waste disposal costs and VOC emissions.

Technical Specifications

Name	Parameter	Name	Parameter
Constant Weight Error	0.3 mg (2 heating cycles)	Residue Range	0 ~ 80g
Balance Range	220 g	Balance readability	0.1 mg
Temperature Error	0.5 °C	Evaporating Temperature	Room Temp ∼ 100 °C
Drying Temperature	Room Temp ∼ 140 °C	Weighing Temperature	Room Temp ∼ 80 °C
Evaporite Mode	Water Bath	Weighing R.Humidity	<20%
Evaporating utensil capacity	100mL (Optional: 50/200mL)	Connect Pipe	¢8mm
Air Pressure	>0.3Mpa	Solvent Recovery Rate	95%
Power Supply	AC220/110V; 50/60Hz
Model	Model Number
Model	ERT-121-C	ERT-181-C	ERT-231-C
Specimen Number	12	18	23
Quantity of Balances	1	1	1
Net Weight	~150KGS	~154KGS	~290KGS
Size	860x750x690mm (LxBxH)
Power Consumption	<10KW

Standard Configuration

Main testing unit (host)

Drying system

Evaporating vessels (12 / 18 / 23 pcs respectively)

Test computer with professional software

METTLER TOLEDO analytical balance (0.1 mg)

Valve suites

Optional Accessories

High‑Efficiency Solvent Recovery Device

0.01 mg Analytical Balance

GMP Computerized System Module

Alternative evaporating vessels (50 mL / 200 mL)

User‑Provided Items

Compressed air source (> 0.3 MPa)

Distilled water

Tap water

Frequently Asked Questions (FAQ)

Q1: What is the main application of the ERT‑C Series?

A: The ERT‑C Series is purpose‑built for total migration testing (GB 31604.8), non‑volatile residue testing (YBB), and loss on drying / moisture analysis (USP <921>, Ph. Eur. 2.2.32). It is not intended for high‑temperature ashing or ash content determination.

Q2: How does this instrument replace a water bath, oven, and balance?

A: It integrates all three functions into one system. Samples are evaporated, dried, cooled under low humidity, and weighed automatically-eliminating manual transfer and moisture reabsorption errors associated with desiccators.

Q3: What does “0.3 mg constant weight” mean?

A: Pharmacopoeias define constant weight as successive weighings differing by no more than 0.3 mg. The ERT‑C automatically repeats the dry–cool–weigh cycle until this criterion is met, ensuring regulatory compliance.

Q4: Why is low‑humidity cooling important for total migration testing?

A: After drying, residues readily reabsorb moisture from ambient air. The ERT‑C cools samples in a <20% RH chamber, stabilizing the residue mass before weighing-critical for accurate migration and LOD results.

Q5: Can the ERT‑C handle alcoholic food simulants?

A: Yes. The instrument is compatible with aqueous and alcoholic simulants. For ethanol‑based methods, the optional solvent recovery device is strongly recommended to control VOC emissions.

Q6: How do I choose between the 12, 18, and 23 workstation models?

A: Selection depends on daily throughput:

ERT‑121‑C: Low‑volume QC or R&D

ERT‑181‑C: Medium‑scale routine testing

ERT‑231‑C: High‑volume QC laboratories

Functions
Constant weight tests for loss on drying, non - volatile substances, residue quantity, total migration, volatile substances, moisture content, soluble and insoluble quantities.
It can replace water baths, drying ovens and balances to achieve constant weight .
Constant weighting requirement in Chinese Pharmacopoeia, Extractives Determination Method" in Part Four of the Chinese Pharmacopoeia、Loss on Drying Determination Method、Total Solids Determination Method、USP40-NF35<921>、YBB 00342002、YBB00132002、GB 31604.8、GB5009.3、GB 8538、DZT0064.9、GBT14415、GBT5750.4、GB/T 9740、GB/T2914、GB5413.39、ISO 759、"Purified Water" in Part Two of the Chinese Pharmacopoeia、EP9.0 WATER, PURIFIED
Features
- Complies with national standards and features a fully automated four-process system: water bath, drying, cooling, and weighing.
- Precise and efficient: Achieves 0.3mg constant weight with just 2 drying cycles. Available with 12、18, 23, 33, 46, or 69 workstations.
- Safe: Indirect heating design to prevent combustion and explosion. Equipped with over temperature power off protection and water level protection.
- Compact: Water bath chamber, drying oven, cooling unit and weighing balance are integrated into one unit, footprint reduction.
- Features patented: heat insulation, moisture proof, and anti-corrosion technology for the balance, ensuring its stability and long service life.
- Digitally set test parameters, fully automated operation without manual intervention. Offers two test modes: constant weight and constant time.
- Equipped with METTLER TOLEDO balance.
- Software: Provides graphical, full process and all element monitoring, along with multiple report formats.
- Optional: GMP "Computerized System" functional module.
- Optional: High - efficiency solvent recovery device.

Specification

Name	Parameter		Name		Parameter
Constant Weighting Error	0.3 mg （2 heating cycles）		Residue Range		0～80 g
Balance Range	210 g		Balance resolution		0.1 mg
Temperature Error	0.5 ℃		Evaporating Temperature		Room Temperature ～100 ℃
Drying Temperature	Room Temperature～140 ℃		Weighing Temperature		room～80 ℃
Evaporite Mode	Water bath		Weighing humidity		＜20%
Evaporating utensil capacity	100 mL (Optional: 50, 200 mL)		Connect Pipe		Φ8 mm
Air Pressure	>0.3 MPa		Solvent Recovery Rate		95% (Optional: Solvent Recovery Machine)
Power Supply	AC220V /110V ;50/60Hz
Model	Model
	ERT-91-C	ERT-121-C		ERT-181-C
Specimen Count	12	18		23
Balance Count	1	1		1
Net Weight	~150kg	~154kg		~290kg
Size (L×B×H) mm	860×750×690
Power Consumption	<10,000 W

- Configuration: Principal Machine, Dryer Machine, Evaporating Utensil, Computer, Professional software, Valve Suits.
- Optional: Solvent Recovery Machine、0.01mg balance.
- Self-provided: Compressed air、Distilled water, tap water..

Keywords:

Integrated Dryer‑Ashing‑Weighing Workstation for Ignition Residue, Loss on Ignition & Ash Content

Determination of Overall Migration Constant Weight Analyzer