Grant GD100 Digital Circulating Water Bath
The Grant GD100 Digital Circulating Water Bath is a precision stirred thermostatic bath designed for general laboratory heating, sample conditioning, incubation, calibration, and temperature-sensitive research applications. Featuring digital temperature control, approximately ±0.05°C temperature stability at 37°C, 0.1°C setting resolution, and active bath circulation, the GD100 provides substantially more precise and uniform temperature control than a basic non-circulating laboratory water bath.
Part of Grant Instruments' Optima series of digital thermostatic controllers, the GD100 can be paired with compatible Grant stainless-steel or plastic baths in several capacities. Its straightforward digital interface, multiple temperature presets, low-liquid protection, and active stirring make it particularly useful for routine laboratory procedures where consistent and repeatable bath temperature is important.
Available used and refurbished from American Instrument Exchange, this Grant GD100 is inspected and tested for reliable heating, circulation, temperature regulation, and controller operation. A 90-day warranty is included.
Key Features
-
0°C to 100°C controller temperature range
-
Digital thermostatic temperature control
-
Approximately ±0.05°C stability at 37°C
-
Approximately ±0.1°C bath uniformity at 37°C
-
0.1°C temperature setting resolution
-
Four stored temperature values
-
4-digit LED temperature display
-
Active bath circulation for improved temperature uniformity
-
Approximately 1.3 kW heater at 115 V
-
Approximately 1.4 kW heater at 230 V
-
Low-liquid float switch protection
-
Visual alarm
-
Two-point user recalibration
-
Simple rotary control and push-button interface
-
Compatible with multiple Grant bath sizes
-
Suitable for general-purpose laboratory temperature control
-
Used, refurbished, and tested by American Instrument Exchange
-
90-day warranty included
Overview
The Grant GD100 combines digital temperature regulation with active fluid circulation to provide accurate and consistent temperature control for routine laboratory applications.
Unlike a basic static water bath, a stirred thermostatic bath continuously moves fluid around the reservoir. This improves heat transfer and helps reduce temperature differences between different areas of the bath, providing more consistent conditions for samples and vessels.
The GD100 controller was designed by Grant as a general-purpose laboratory thermostat and was available with multiple bath configurations. This modular design allowed laboratories to select an appropriate working volume while maintaining the same basic digital temperature-control platform.
Operation is intentionally straightforward. A 4-digit LED display shows temperature, while a rotary control and push-button interface provide access to setpoint adjustment and other functions. The GD100 can store four temperature values, allowing frequently used operating conditions to be recalled without repeatedly entering the desired setpoint.
Low-liquid protection and visual alarms add protection during routine operation.
Key Specifications
| Specification |
Details |
| Manufacturer |
Grant Instruments |
| Model |
GD100 |
| Equipment Type |
Digital stirred thermostatic bath/circulator |
| Temperature Setting Range |
0°C to 100°C |
| Temperature Stability at 37°C |
Approx. ±0.05°C |
| Temperature Uniformity at 37°C |
Approx. ±0.1°C |
| Setting Resolution |
0.1°C |
| Display |
4-digit LED |
| Stored Temperature Values |
4 |
| Temperature Control |
Digital |
| Heater Capacity – 115 V |
Approx. 1.3 kW |
| Heater Capacity – 230 V |
Approx. 1.4 kW |
| Internal Bath Circulation |
Yes |
| Low-Liquid Protection |
Float switch |
| User Recalibration |
Two-point |
| Bath Capacity |
Depends on installed Grant tank |
| Mechanical Refrigeration |
No |
| Electrical Requirements |
Verify individual unit nameplate |
| Warranty |
90 days |
Common Applications
The Grant GD100 is suitable for a broad range of laboratory procedures requiring stable and repeatable heated bath conditions. Typical applications include sample warming, incubation, reagent conditioning, media preparation, chemical reaction studies, materials testing, calibration procedures, quality-control testing, viscosity-related work, and general laboratory research.
Active circulation makes the GD100 particularly useful when multiple samples must be maintained under similar thermal conditions within the same bath.
Instead of relying only on natural convection, the circulator continuously moves heated fluid throughout the reservoir. This improves thermal transfer and helps reduce differences between the temperature near the heater and the temperature elsewhere in the bath.
The GD100 can therefore provide a useful step up from a basic laboratory water bath for procedures where temperature consistency and reproducibility are important.
Ideal Laboratory Types
The Grant GD100 is well suited for biotechnology laboratories, pharmaceutical facilities, chemistry laboratories, clinical research groups, analytical laboratories, quality-control departments, materials-science facilities, industrial R&D laboratories, teaching laboratories, and academic research environments.
Its combination of precise digital control and relatively simple operation makes it particularly useful as a general-purpose shared laboratory bath.
The availability of multiple compatible reservoir sizes also made the GD100 platform suitable for laboratories with different sample volumes and working-area requirements.
Temperature Control & Uniformity
The Grant GD100 provides digital temperature control from approximately 0°C to 100°C.
Grant specifies temperature stability of approximately ±0.05°C and bath uniformity of approximately ±0.1°C at 37°C under defined test conditions.
These specifications describe two different aspects of bath performance.
Temperature stability indicates how closely the bath maintains temperature over time at a given location. Uniformity describes how consistent the temperature is across different areas within the bath.
The GD100's active stirring system helps improve both heat distribution and thermal transfer by continuously moving bath fluid around samples and vessels.
Temperature can be set in 0.1°C increments, while four stored temperature values allow frequently used conditions to be accessed more conveniently.
The controller also supports two-point recalibration, allowing its temperature measurement to be checked and adjusted against appropriate reference standards.
Heating & Bath Performance
The GD100 provides approximately 1.3 kW of heating capacity in the 115 V configuration and approximately 1.4 kW at 230 V.
Actual heat-up time depends on reservoir capacity, starting temperature, fluid volume, sample load, bath insulation, ambient conditions, and whether a lid is installed.
Grant recommends water for many routine applications between approximately +5°C and +80°C.
At temperatures above approximately 60°C, using a suitable bath lid can reduce evaporation and heat loss. Near the boiling point of water, evaporation becomes increasingly significant and can affect temperature control.
The GD100 itself does not contain mechanical refrigeration. Operation below ambient temperature therefore requires an appropriate external or accessory cooling method.
Safety & Ease of Operation
The Grant GD100 was designed as a straightforward general-purpose laboratory controller.
A float switch monitors fluid level and helps protect the system against operation with insufficient bath liquid. The controller also provides a visual alarm to alert the operator when attention is required.
The digital interface uses a simple rotary control with push-button functions rather than a complicated programming system, making routine temperature changes relatively quick.
Stored temperature values are particularly useful in laboratories that repeatedly use several standard bath temperatures.
These features make the GD100 appropriate for shared laboratory environments where multiple operators may use the same bath for different procedures.
Refurbishment & Testing
This used Grant GD100 Digital Circulating Water Bath is refurbished and tested by American Instrument Exchange before shipment. Our technicians inspect the heater, circulation system, digital temperature controller, LED display, temperature sensor, reservoir, electrical components, low-liquid protection, and applicable safety systems.
Temperature-controlled equipment is tested using NIST-traceable probes and data loggers. The GD100 is operated under simulated laboratory conditions to evaluate heating performance, temperature regulation, bath circulation, controller operation, and overall system stability.
The bath and accessible fluid-contact surfaces are cleaned and inspected before shipment.
Customers requiring the GD100 for a particular operating temperature or sample-conditioning procedure are encouraged to provide those requirements before shipment. When practical, American Instrument Exchange can incorporate customer-requested operating conditions into final testing.
A 90-day warranty is included with this refurbished Grant circulating bath.
Choosing the Right Circulator or Water Bath
The Grant GD100 is particularly well suited for laboratories that need more precise temperature control and better bath uniformity than a conventional non-circulating water bath provides.
Its active circulation system continuously mixes the bath fluid, while digital control provides convenient temperature setting and monitoring.
Bath capacity is another important consideration. Because Grant offered the GD100 controller with several compatible reservoir sizes, buyers should verify the capacity and working dimensions of the particular bath included with the unit.
The primary limitation is the lack of integrated refrigeration. Laboratories requiring routine operation below ambient temperature may be better served by a refrigerated circulating bath.
For general heating, incubation, calibration, sample conditioning, and other applications up to approximately 100°C, however, the GD100 provides an effective combination of digital control, strong temperature stability, active circulation, and straightforward operation.
American Instrument Exchange can help compare available used and refurbished circulating baths based on temperature range, bath capacity, stability, uniformity, heating power, and intended application.
Related Equipment
American Instrument Exchange stocks a range of laboratory circulators, including Grant circulating baths, heated circulators, refrigerated circulators, recirculating chillers, and immersion circulators. Laboratories considering the Grant GD100 may also want to compare available laboratory water baths and other refurbished temperature-control equipment for laboratory applications.
Grant GD100 Frequently Asked Questions
What is the temperature range of the Grant GD100?
The GD100 controller has a temperature setting range of approximately 0°C to 100°C. Because it does not contain mechanical refrigeration, operation below ambient temperature requires an appropriate external cooling method.
How stable is the Grant GD100?
Grant specifies approximately ±0.05°C temperature stability at 37°C under defined test conditions.
How uniform is the bath temperature?
Grant specifies approximately ±0.1°C temperature uniformity at 37°C.
What is the temperature setting resolution?
The GD100 allows temperature settings in approximately 0.1°C increments.
How many temperature presets does the GD100 have?
The GD100 can store four temperature values, including the operating setpoint and three additional adjustable preset temperatures.
What size is the Grant GD100 bath?
GD100 identifies the temperature-control platform rather than one specific reservoir size. Grant offered the controller with several stainless-steel and plastic bath configurations, so the capacity of the individual AIE unit should be used when determining working volume.
Is the Grant GD100 refrigerated?
No. The GD100 does not incorporate mechanical refrigeration. An appropriate external cooling system is required for controlled operation below ambient temperature.
Does the GD100 provide active circulation?
Yes. The GD100 is a stirred thermostatic bath controller and actively circulates fluid within the bath to improve temperature distribution.
What is the difference between the Grant GD100 and GD120?
Both are digital Grant Optima thermostatic controllers, but the GD120 provides additional functionality, including a pump designed for external fluid circulation. The GD100 is primarily intended for internal bath circulation.
Does this refurbished Grant GD100 include a warranty?
Yes. This used Grant GD100 is refurbished and tested by American Instrument Exchange and includes a 90-day warranty.
